Peak just sent me one of their solid wood Playstation 3 guitars for Guitar Hero and Rock Band. The Starpex is the same scale as a real guitar and uses the same sorts of parts, when possible. For instance the tuning pegs are real as is the whammy bar. Of course all of this realism makes for a pretty heavy kit, but I think it's worth it. The controller works with both the PS2 and PS3 and comes with wireless and wired options. I'll make sure to weigh in with my opinion after I've had some time to go a few round with it on the Playstation 3.
I have a 3rd rock band guitar lying around that I would like to find a cheap electric guitar to mod. But I wont drop $100 bucks on one to cut up, so for sure I wont drop the money they want on one already done. But I would like the satisfaction of modding one.