hi mate just spent the morning measuring up my current wheels, looks like the BBS you have for sale WILL fit under an SC (protrudes outwards 30mm all round, inwards 7mm at the front) - to be honest they will fit better than they would on a 964 turbo (60mm outwards on rear, 47mm outwards on front).
if you're willing to ship to Australia, i am quite interested

good looking wheels!