So you want to make a guitar that makes horrible feedback, or some weird kind of prepared string monstrosity?
For building a new guitar, though, ebay is a haven for old pickups and nasty project guitars. I looked around for you, and heres some cool stuff:
http://cgi.ebay.co.uk/OLD-JAPANESE-PICK-UPS-AND-PANEL-GUITAR-PROJECT_W0QQitemZ190099527322QQcategoryZ2384QQrdZ1 QQcmdZViewItem
Old japanese pickups with switchers and whatnot
http://cgi.ebay.co.uk/Project-Guitar-Body-Maple-Cap-RG-Frank-Gambale-Style_W0QQitemZ200097427138QQcategoryZ52473QQrdZ1Q QcmdZViewItem
Brand new unpainted body. Weird shape. It has a weird cavity space though you'd have to make more room in there to put your own pickups in.
http://cgi.ebay.co.uk/F3NDER-Strat-Style-Guitar-Neck-22-Frets-Brand-New_W0QQitemZ190099462152QQcategoryZ42455QQrdZ1QQc mdZViewItem
Nice guitar neck, ish.
If you did it right you'd save a bundle. Gotta do some research too though.