Thanks for all the input everyone. I definitely going with an Edelbrock Thunder Series AVS. Lots of tuning options that way. Sounds like a 650 is the way to go seeing that Edelbrock doesn't list a 600 anymore
I think that's a very smart choice. While it maybe a "little big" it can be tuned easily and will leave you with a good bit of room to grow if you decide to swap engines down the road.