Just like the LS build, you can use pretty much any party members that you want but there are some of them that provided very good support to this build.
The only skill really needed for party members to minimize gear switch is to have a high Demolition skill to recover mines. Main Character already covers Repair for part cost and T3-M4 can supply more Computer Spikes than we end up needing.
Personnal party members progression:
Carth -> Carth/Mission -> Carth/Zaalbar -> Carth/Bastila -> Carth/Canderous
Canderous/Mission, Bastila/Canderous for the Ruins
Canderous/Mission, Jolee/Mission
Bastila/Mission, switch Bastila for Jolee for Korriban
Bastila/Mission, can also use heavy weapon Juhani from this point, Canderous for the Star Forge
As we are playing a DS build, the LS wisdom stuff is all available for her thanks to her Light Side alignment. Sadly this awesome build will get changed to a pretty bad one once we get her back on the Rakatan temple but thanksfully it is only for the Star Forge portion. I like to also keep Korriban last to maximize my time with her except for the Jolee portion on Kashyyyk. She is going to be an amazing force user until we lose her, only inferior to Jolee for the amount of powers she can learn, which isn't a problem either in the end. Her role is to keep everything debilitated while providing adequate DPS using a double bladed lightsaber. I like going with Stasis Field as her great LS DC allow her to work well against Fortitude saves and Immunity:Mind Affecting while the PC covers Insanity this time for the Will save.
Script: Jedi Support. (her and Jolee only)
Attribute: All Wisdom
Skills: Automatic (Awareness and Treat Injury)
Feats (assuming you get her to 17, 4): Master Two Weapon Fighting (2), Master Flurry (2)
Powers (also at level 17, 14): Cure (1), Destroy Droids (3), Master Speed (3), Master Valor (3), Stasis Field (2), Force Breach or Force Choke (2).
Gear: Circlet of Saresh, Qel-Droma Robe, Double Bladed Lightsaber, Advanced Stabilizer Gloves.
For the Star Forge portion, build her a Heart of the Guardian + Krayt Gragon Pearl + Upari double bladed lightsaber and just go with her awful build.
Same as the LS build, Jolee is a total beast from the moment you get him. Goal here is to make him learn Kill as soon as possible (level 12), which should be possible if you completed a few side quests for credits and gear on Korriban before going on Kashyyyk. It will affect Mind Affecting immune enemies. I used a dueling melee setup with him, but you could also use an Heavy Weapon build using a Baragwin Assault Gun or Baragwin Heavy Repeating Blaster. Same role as Bastila as long as you have him in he end. Make sure to remove his immunity to Mind Affecting and Critical Hit gear for the Rakatan Temple, else he might end your life on RCM Impossible difficulty.
Script: Jedi Support.
Attributes on level up: All Wisdom
Skill: All into Demolition as we want to minimize gear switch if not having Mission with us.
Feats (4 by level 19): Master Dueling (1), Improved Toughness (2), Profiency: Light Armor (1).
Powers by priority (16): Kill (3), Destroy Droids (1), Stasis Field (2), Master Valor (2), Master Speed (3), Force Immunity (2), Death Field (2) Heal (1). Can also skip heal and go for Insanity instead of Stasis Field if you want but i like getting something different than my PC for the previously mentionned reasons.
Gear: Single Bladed Lightsaber, Demolition Sensor for mines, else Bothan Sensory Visor, Nerve Amplifer Belt, Advanced Stabilizer Gloves, best jedi robe.
Same as LS, Mission is amazing if used well. She has amazing defense and is the best tank for most of the game on Impossible due to that but lack a bit of damage at the start, which i why i prefer using Zaalbar to end fights faster at that point on Taris. She can also take care of any skill checks that you'll need. She pairs super well with Bastila and Jolee with their amazing immobilizing powers, which makes her deal sneak attacks constantly and we want to abuse that for insane damage (9-54 extra damage per attacks). Careful when you fight her however as she starts in your back... you know what this means.
Attributes: All strength
Skill: All class skills maxed at least until 20, then max computer use (will be much lower as a non-class skill).
Feats (6): Master Two Weapon Fighting (3), Master Flurry (3).
Gear:
Weapon: Echani Ritual Brand -> Ajunta Pal's Blade
Armor: Bothan Sensory Unit, Nerve Amplifer Belt, GenoHaradan Power Gloves, Genoharadan Mesh Armor.
Juhani has the potential to be the best ranged character in the game by far with some insane firepower, which in my opinion makes her even better than using her with a double bladed lightsaber. While more damaging, she tend to engage much faster with a ranged setup and cleave between defeated enemies much better. With the addition of force powers, she can also buff herself to be very resilient while debuffing strong foes into nothing. Just like Jolee, make sure to remove her immunity stuff and ideally make her use a basic single bladed lightsaber for the Temple Summit.
Attribute: All dexterity
Skill: Automatic (awareness and threat injury)
Feats (6): Weapon Profiency: Heavy Weapon (1), Master Rapid Shot (3), Implant 2 (2).
Powers by priority (14) : Heal (2) Master Speed (2), Plague (2), Force Breach (2), Force immunity (2), Death Field (2).
Gear: Baragwin Assault Gun -> Baragwin Heavy Repeating Blaster for weapon, Heavy Targetting Optics (Korriban Czerka shop), Advanced Stabilizer Gloves, best Jedi Robe so Qel Droma robe post Leviathan, Nerve Amplifier Belt, Retinal Combat Implant.
Canderous lack defense to consistently avoid damage early on but get nearly unstoppable for the Star Forge, thanks to Improved Energy Resistance and his amazing damage. I would advice against taking him at any time before however just because the T1 characters are in every way better, but he's the best choice for DS Star Forge. He can still be used for the whole playthrough and you can spend his points into demolition if you want and he will perform very well. If it wasn't that he's the best late game companion for Dark Side, i would again leave him at the top of Tier 2 but he deserves a little more this time.
Attribute: All Strength
Skills: All Treat Injury (automatic) or Demolition (many other party members can take care of that)
Feats (13): Master Two Weapon Fighting (3): Weapon Specialization Melee Weapon (2), Master Toughness (2), Master Critical Strike (3), Master Conditionning (3).
Gear: Vibro Double Blade -> Krath Double Sword -> Baragwin Assault Blade/Genoharadan Poison Blade/Bacca's Sword while dual wielding. Calo Nord's Armor -> Heavy Exoskeleton fully upgraded, Bothan Sensory Unit, Nerve Amplifer Belt, GenoHaradan Power Gloves.
Still the MVP of Taris for sure but lose effectiveness the further you progress. Choosing Improved Power Blast is a must on Taris, simply queud one per target and watch them fall like flied. Once you get to Dantooine however, no real reason to use him until the Leviathan, where he will perform decently as a Heavy Blaster user.
Attribute: 1 into intelligence at level 8, rest into dexterity
Skills: Max demolition then Treat Injury. He will save you from switching gear on the Leviathan.
Feats (13): Improved Power Blast (1), Master Two Weapon Fighting (1), Master Toughness (3), Master Rapid Shot (3), Master Conditionning (3), Weapon Specialization: Heavy Weapon (2).
Gear:
Weapon: Carth Blaster/Bendak Blaster -> Dual Mandalorian Heavy Pistol -> Baragwin Assault Gun -> Baragwin Heavy Repeating Blaster if you want to keep using him.
Armor: Military Suit (buy as soon as you get on Taris) -> Davik's War Suit -> GenoHaradan Mesh Armor, Advanced Stabilizer Gloves, Nerve Amplifer Belt, Bothan Sensory Unit or Heavy Targetting Optics until you get the Feats.
Sadly he lacks the feats to be better in combat. I found a very good way to use him however, as droids can use the Carbonite Projector Mark II which allow you to paralyze any foe for a minimum of 9 seconds if saved and 15 if not, making it perfect for Bandon so you can land Sneak Attacks on him without having to use Force Breach. He's now my favorite to use to rescue the party on the Leviathan as he keeps all of his gear and have access to his unlimited Baragwin Droid Shield, making him pretty much immune to any damage on that level on top of his insane defense by that point. His damage is also good enough to kill everything with a single Master Rapid Shot using the Baragwin Assault Gun. Sadly you're stuck with Bastila on the Star Forge and Canderous is a much better pick as a second companion.
Attributes: All dexterity.
Skills: Max Repair and either Demolition or Computer Use.
Feats (4): Master Rapid Shot, Improved Toughness (1)
Gear: Chuundar's Bowcaster-> Baragwin Assault Gun->Baragwin Heavy Repeating Blaster. Composite Heavy Plating, Baragwin Droid Shield, whatever you want for the rest.
Borderline usable again and really lack the defense and staying power that others have. He's again very good to dispatch of the gang members on Taris but doesn't shine much after that. A notable advantage is that he's the first efficient implant user, which means easy Mind Control immunity with a Nerve Enhancement Package which can be useful against the Sith Thugs on Korriban when looking for a medalion.
Attribute: All Strength
Skill: Max Demolition, Max Treat Injury, rest into computer use or whatever you want.
Feats (8): Master Two Weapon Fighting (3). Master Flurry (2), Master Toughness (3)
Gear: Nerve Enhancement Package/Belt, Retinal Combat Implant, same as Canderous for the rest.
Again, only useful to unlock the door to the sith base on Taris.
Attributes: Dexterity
Skills: Automatic (max everything)
Feats (5): Improved Two Weapon Fighting (2), Master Toughness (3).
Gear:
Weapons: Best pistols you can find, the best being Cassus Fett's Pistol and Saul's Sith Assassin Pistol, Baragwin Flame Thrower.
Armor: Composite Heavy Plating, Baragwin Droid Shield, Superior Targeting Computer.