what about a 5th gen (92-95) civic VX (lightest body style) for around 2-3 grand (depending on condition) and add a B20z (~$1200). Run a little xtra wiring, throw on a Vtec head (~$200-300) for a CR-Vtec for lots o' hi-RPM power. Stock B20z has 150hp and 148tq. Add to that some after market mods and zoom, zoom, zoom!!!
Since you want to scrap the stock engine anyway, I'd look at an auction in your area. Check the yellow pages and newpaper for bank auctions, impound lot auctions, theft recoveries (depending on your state), etc. You should get a decent body and interior for close to $1000 (maybe less). Since you'll be changing everything that matters (engine, tranny, susp, wheels, tires, gauges, shifter, exhaust, etc) there really isn't any sense in paying for something you're going to either throw away or sell for 1/3-1/2 what you just paid for it in the car.
Good luck!!