Take heed of what Henry say's. He's been there and done that. Even has the T-Shirt.
Your not going to find a "Good" body cheap. If you buy a cheap body you will be hatin life. I went through a couple of em.
Both GMT and New Age make a great 5 window.
If your going with a 3 window or a roadster and want the best? Westcott is your first choice. However there are good bodies out there for less, so don't get upset if you can't afford 15K$ for a coupe.
Put the WHOLE thing together like your going to drive it first. Steering, brake/fuel lines, engine, body/hood, tank glass, interior window mouldings, dash etc.
Then worry about the paint when it's correct.
You can always contact anyone here for more info.
And remember when you die, thats it. Your not comming back as a hot rodder. Party is OVER! So get while you can.