OK, I think some on this page might object but here's a few points where to start.
1) Start with an idea of exactly what you want to do with this vehicle. If it's sunday fun driver and you want good sound you'll need different parts from if you need your car to run every single day and just want a bit of fun at the weekends.
2) Remeber, you can only chose two of the following: good - fast - cheap.
3) Buy iron heads, closed chamber, not over 64 cc chamber, not over 200cc intake runner volume. Big valves are OK, but not a must, as you might get bad shrouding and thus get less flow than with small valves depending on the exact casting.
4) Get your powerband down low and make it nice and wide. Build for intake speed, not only for amount
5) don't go over 650 cfm on the carb, but get a good one which you can tune nicely (Holley's are a bit fiddly sometimes, but a good book will help. Edelbrocks are more or less foolproof)
6) flat top pistons, try not to exceed about 10:1 static CR, with nice quench you'll be running safe on pump gas until 10:1.
7) When you've got a good idea of what you want the engine to do call as many cam manufacturers as you can find and get their advice. I'm by no means expert enough to say what cam you need for your purpose. Then when you have the specs from as many companies as possible find a suitable compromise in specs and get one within these specs which fits in your price range. The cam manufacturers are experts and if you find a compromise between 3 or 4 manufacturers that'll keep you on the safe side.
8) don't rush anything.
Wish you a lot of fun with your build and as always, all questions are very welcome!
Greetz,
Mad