probably your best bet is to keep an eye on your local Craigslist/classifieds/used car dealers. Cars of such little value don't often even make it onto ebay, as they are probably worth just as much in the scrap heap, especially if they are not running. Cars that where cunning where probably clunker specials, so it might be hard to find a car with that budget. Your best bet might be something like an old Beetle. Older cars are easier to work on, and if they have a big enough fan base, parts should be easy enough to find. Other possibilities: Mustang II, 70's Celica, AMC Eagle, Dodge Dart, Chevy Corvair.
Now I understand these where probably not the cars that you where hoping I would tell you to get, as you where probably inspired by The Fast and the Furious (who else would want RWD with body kits and seats), But with your budget and level of experience, the above mentioned cars are probably a better fit for your needs.