I would HIGHLY recomend the edlebrock carburetor, 600cfm.
Go ahead and buy the tuning kit with the carb, and follow the instructions.
It will be more reliable and consistant than a holley, and will NOT leak, since there are no gaskets below fuel level. They are also not prone to power valve failures from the occasional backfire as the holleys are.
I've rebuilt tons of holleys, and they are easy to work on, but, can be tempermental and always seem to leak eventually. My friends that have gone with the edlebrock are very happy with the reliability and performance, especially on a daily driver type vehicle.
Some carbs will work good for your particular application out of the box, but most will need some tuning, that is why I say to get the tuning kit and go through the manual step by step. They make it easy to trouble shoot problems and get the carb to perform at it's best.
It's not rocket science, just take your time and be methodical about it.
ENJOY