Cybermatrix has a great idea. Locost 7 or a 7 rep is what I've dreamed of for a loong while. Ultimate power to weight. But no no as a daily.
First thing I can think of if you want cheap parts and availability is a mk1 golf. Everything about it is cheap as chips and very simple to work on. If you can live with the fact that it'll probably be broken into and there's millions of them.
Chuck in an ABF 2L 16v and turbo it. Hell, those things without turbo's take out civic's with turbo's! Saw it on samrand the other night...