This section includes the best armor, weapons, and mods that can be crafted or found across both The Sky Breaker and Secrets of the Spires. It is meant to be followed once the second DLC on a given save has been started, and more realistically will be followed once the second DLC is completed.
Read this first to make sure you're set up for the best crafting: Onboarding
To create a sense of linear progression no matter what order you choose to play these two DLCs, the game uses changing stats for materials, gear, and gear mods. The first DLC you play in a given save file will always have lower stats, and the second DLC you play in a given save file will always have higher stats. Additionally, the first DLC's stats will be raised once you begin the second.
As a consequence, the firearms and gear mods you'll be aiming for will depend on which ones you have not received by the time you begin your second DLC. Both sets of crafting designs are largely equal with a few exceptions, in which case only the more powerful design is listed.
Personally, I recommend playing The Sky Breaker first and then Secrets of the Spires for the following reasons:
Spires has more mods to choose from in most categories.
Skybreaker doesn't have mounted crossbow mods; if you get them all in spires with their lower stats, that's it.
Spires has an arm and head mod for SID while Skybreaker only has an arm mod.
Spires' best firearms are stronger than Skybreaker's. You can still trade spare parts with So'lek for the best ones either way, but they're expensive.
Head: 880
Torso: 880
Arm: 770
Waist: 880
Leg: 859
Longbow: 544
Shotgun: 650
Assault Rifle: 45
Spear-thrower: 907
Heavy Bow: 757
Shortbow: 484
Ikran Head: 695
Ikran Saddle: 695
Ikran Tail: 695
Crossbow: 422