That's a big bore for use with a boosted setup. I'd stick with the stocker first, then step up to a B-car one. If you compare the piston area of a b-car caliper (2.75" bore IIRC), the piston area is not far off from 4 smaller ones on the Wilwood.
The only thing you will lose with that big Wilwood master is pedal resolution (for lack of a better term). All that boost and all that volume may give you a setup that is full of boost, and hard to modulate w/o locking up. So maybe see how the stocker feels first? :dunno:
Just a thought.. since it's free advise, you might be getting what you paid for..