Compression Ratio

For my goal, do I really need more than a 9.5:1 cr? I'm not going for big power, but I do want a improvement over stock.
with what I can glean from your posts, no. you should be just fine with something in the the 9.5 area.

realistically, probably the best build you could do would be a magnum 360 with a +1 cam, light head work and a dual plane manifold with 750ish carb. that would be *plenty* for what you are and would meet your criteria almost perfectly.

it wouldn't cost a fortune to build, parts are inexpensive and easily available, it'll run on pump gas all day long and produce decent power while being reliable.