Carb recommendation help Slant 6

For good performance and easy of installation it's hard to beat a super six 2 bbl. You could get an aluminum manifold, change to a chrome 273 style air cleaner and it would look "racy".
If you are sold on the 4 bbl, I would do a 390 Holley or a small Edelbrock carb. Your engine base sounds good so you don't want to kill it with too much fuel. The object is to have a good running car that is fun to drive, not a bunch of problems that kill your joy. Once you get it running then you can make small changes to get some more performance.
Sorry I don't have specific part numbers to give you on carb choices.