ive fitted r32 front brakes on my s3 and they bolt straight on and even fit under the standard 17'' wheels. they are miles better than the 312mm setup and TBH for road use they feel just as good as brembos!!
Enjoy buying the discs tho at £200 each
so you dont even need the carriers? can you really notice the difference? you can get r32 calipers pretty cheap now, deffinitely worth it imo if they're any better then the S3's standard set up