Fortunatly, you have a number of good choices for you to choose from. Lone Star, Factory Five, and Backdraft are excellent choices, and can be built (or bought) for a reasonable price.
For me, Factory Five comes to mind, for obvious reasons. Especially when you say "donor". A nice, powerfull, relaible, FFR can be built for <$20K. For a donor, you can use any Mustang from '87-'03. With their kit and a rolled mustang, you have every single part you need except paint. Every part, bolt, screw, sensor, and wire. If it's not in the kit or on the Mustang, you don't need it.
Imagine a nice roadster with a bone stock 4.6L V8 and a T45 6 speed. Powerfull, fun, great looking, and will easily get 20+mpg for 100K miles or more. And if you want more power or better handeling, just open a catalog. Does it get any better than that?
The Backdraft and Lonestar can be built to the same level, for about the same money. But it's a smidgen more difficult, because you have to source more parts from a variety of sources. They're still excellent options, though.
As said above, the real bargains these days is to buy one already built. But where's the fun of that? It's hard to decide what is more fun, building, driving, or racing my FFR. I'd love to build another car. But I wouldn't want to be without the car for 2-3 years while I build another one.
Besides, do you trust a guy you don't know to build your car?
