R32 brakes are twin pot, with 2 pistons on the same side of a sliding caliper. I think the discs are 334x32mm. they're big anyway.
Old heavy design with iron calipers, and still sliding like the S3 312's, but much more power. Only down side is hugely expensive to replace discs, and very heavy.
Better off with brembos if you have the chance, although for a road car R32's might be pretty good.
Pretty sure they will fit under 17'' Avus too