Some advice

If this is a street engine, it is easy to overdo it. A big square-bore carb doesn't cost much more than a smaller one, likewise an aggressive cam grind isn't that much more than a tamer one. Unless something is done to the raise compression ratio and the rear gear ratio, the sum of the components becomes less than the whole. If money is an issue, suggest bumping the compression ratio now, catch the rear gear later.

For the rear end, a 3.23 to 3.55 will work on the street. Compression ratio should not go past 9.5:1 with cast iron heads, 10.5:1 with aluminum heads and pump gas. For cams, take your pick from those that have a 215º-225º duration at .050". Remember to budget for springs and keepers while you're at it. For carburetors, it's kind of a toss-up for me. A 625-650 cfm will yield better throttle response, a 750 cfm will give you better top end. Automatic transmissions tend to work better with a vacuum operated secondary.

If bumping the compression ratio and rear gear are not in the cards, suggest going with a 340-spec cam and a 650 cfm carb with a vacuum (air valve) secondary.