There are many other micro machine star wars ships which are close enough in scale to use with SSB. For the most part they are class 3 and 4 ships. The micro machine versions of class 1 and 2 ships are too small. I am only including the ones that can be used as different ships than those already available in SSB (micro machines such as x-wings, TIEs, etc are not mentioned here, but the corellian corvette is because it can be used as a CR70)
Micro Machines ships that are roughly in the SSB scale (most can be found on ebay but some are very rare):
Twin-Pod Cloud Car
Rebel Blockade Runner/Corellian Corvette (Slightly smaller and different shape than the SSB version so it can be used as a CR70 instead of CR90)
T-16 Skyhopper
TIE Scimitar
Hapes Nova
Z-95 Headhunter
Hound's Tooth (YV-666 light freighter)
IG-2000
Stinger (Conqueror-class assault ship)
Imperial Lander (Sentinel-class landing craft)