You can always ask someone like GoaFan77 for help on that. He is the maker of the Star Wars Requim mod and see if he can lend some or give you a direction for some.
Just a heads up, Goa hasn't actually made any of Requiem's models, rigged them sure, but make them not so much.
Though as for the OP, Sins of a Galactic Empire has a good bunch, from EJ and Warb_Null, among others. EJ is fine with people using his stuff, as long as proper credit is given. iirc Warb is the same way, though I'd ask him to be sure personally (he's on these forums). Though I have to ask, out of curiosity, what is your intention with this project? As there's already both a total conversion and an "addition" to stock Sins.
Does any 3d model file work on in Sins? If then you could probably look around the Star Wars Empire at War filefront site and rummage around that pool of models there.
You can use EaW models, though you'll need to convert them from .ALO to .obj, then rig them up in Softimage, and afterward convert the .XSI to .mesh. To convert them, I personally go from: .ALO -> .3ds -> .obj. I use 3D Object Converter and 3DS Max to do this.
