Accufab has flow numbers on their website, find an engine CFM calculator online and plug your specs in and compare. Will mostly be dictated by displacement, the S/C will improve volumetric efficiency so you can be a little undersize and still make the power. Will also help to have an idea what HP you expect out of the engine. You do want to taper down from the MAF size generally but with the S/C you're also not worried about creating velocity. 90mm is a pretty big TB so you'll probably be smaller than the MAF anyway.
I agree, though OP has not said if it's a race or street car. A smaller TB would reduce the throttle sensitivity and make it a little more streetable without giving up overall power.