Need some advice on choosing an engine

Hey Gary, at the risk of sounding like a party pooper, sorry if I did earlier. I myself love a small block and would say to use one BUT a lot depends on the owner of the car.

It is hard to beat cubic inches. AKA big block.
On the flip side, you could save a few pounds with a small blocknthat can be stroked to more than a simple 4.00 arm provides.
There are 4.125, 4.15 & 4.25 stroke cranks for small blocks out there now.

Couple that with the bore size and you can get a decent amount of cubes quick.
Add Victor heads and 1-7/8 headers with a reasonable roller cam and I think it is very doable.