318 build suggestions?

A friend of mine has a 318 short block .060 over, zero deck engine that we’re going to build. It’s going into my ‘67 Barracuda convertible, which will be running a 904 automatic and 3.91 gears with 28” tires. Couple of questions:
1. What’s a fair price for the short block?
2. What’s the best top end combination out there to make 400 horses with it? Thinking some aluminum heads, and would prefer a complete package (cam, lifters, roller rockers, etc).