Never liked the slotted variants for the road personally, they are noisy, grab some EBC Yellowstuff pads with some MTEC drilled only discs, or if you don't mind being illegal some Ferrodo DS2500 / Mintex 1144 pads... get a fluid change too
Step Ups from there... R32 calipers > NQSBBK > BBK
BTW, those aren't S3 sized discs, S3 are R32 in size so 345mm on the front. 8P at least