If you just want a budget street oriented build use the short block and heads you have, pick up a 268h cam, a set of headers, an HEI ignition, and dual welded thrush mufflers. It'll have a moderate "hotrod" sound but be very street friendly, durable, and easy to build.
Since its street use the only other thing I may consider is converting to EFI, even throttle body injection will be an improvement over most carbs.
That combo is nothing new or hightech, but its reliable and cheap. The mufflers will give you the sound you're looking for, you may need to adjust the idle down to about 600rpm though.