audi S3 EFR 6758 stroker

Very nice collection of parts for your build, love the brake set up. :)
 
Not sure what the piston sizes are on the 4 pot rears compared to the OEM rear single pot but you don't need a bigger MC with the front 6 pot 18z calipers. Pedal travel on mine is as good, if not better than the OEM calipers I removed.