This is a very interesting article that applies here.
http://www.hotrod.com/articles/how-to-pick-the-best-carburetor-for-a-street-strip-car/

There are a lot of carb builders around and everyone will have a different opinion on who to use (and not use). But it is interesting to note that they all use the Holley 4150 platform to build from. Is there anyone building custom carbs off the Carter AFB or AVS base?

A google search will bring in a lot of info on carb builders. But, the opinions/experiences on them are all over the place and really do not help narrow down which one to go with. And a lot depends on how good a tuner you are. The better the tuner, the less he has to be concerned with what calibration he starts with. But a less experienced tuner needs to get a carb as close as possible.

Thumperdart, Holley, ProForm, Willy's, AED to name just a few.