Carb size/ brand

Here's a slightly different way to look at it. The main air bleeds can be adjusted to get the AFR flat through redline so don't worry about that. A larger carb will have less restriction at WOT than a smaller carb. If fuel distribution and vaporization in the cylinders is really good, less restriction will make more power. But a little restriction (talking 1/2 - 1"Hg more) can help distribution and atomization which produce more power on setups that need that.
I agree with the suggestion to work with Dom or Mark W. It will save you time and money in the long run.