There's a nice build-up for a 408 over in the archive's. You will need to give more info. to get a good response to what to build. Here's just a start:
1. What gears/trans/stall converter?
2. Percent street/strip use.
3. Heads:
A. What pistons?
B. The Edelbrocks are a great "compromise" and a good choice out-of-the-box for street use. Just remember, you will give up about 1 point static compression due to the fact they are aluminium.
4. Torque vs. h.p. vs. rpm range
5. the big one - how much $$$ do you want to spend?
This is no way a difinative list, but should start the dialogue
Mac.