i use blender3d, it makes decent uv maps, so you can paint on the object (but the painting app built in stinks)
use blender to import your objects then go into edit mode and make your seams, then go into uv map mode, and unwrap using LCSM maps, then open up another screen on the right and choose unwrap again, then paint. (if you don;t get me, i dont blame you. Blender is kind of hard to learn, but after you learn it, you need to discover. Download and use youtube for tutorials
Play the games the masters play: MKZn and 3-B promo
http://www.3bpromo.tk