I'd say go with a FWD honda, nissan, dsm. They are generally lighter and cheaper. The drivetrain loss of being FWD will help a bit and should be fine as a "roll" car also most can be made pretty powerfull for cheap. A honda hatch with a B18/turbo, Nissan sentra or other fwd sr20 car, and the 4g63 cars. When you are on a budget it is really more about the money you save doing as much of the work and fabrication yourself than buying the parts to get the car built.