It all depends on how much you are willing to spend and how much upgrade you need for the type of driving you do.
If you have £4.5k available, have 19" alloys and thrash the b0ll0cks off it at track meets and sprints, then you could go the full hog and fit RS4 ceramic brakes

For £2.5k and 18" alloys and do the odd track day with fast/spirited road driving then AP or Brembo's are the order of the day.

If you just drive your car spiritedly then R32 upgrade stoppers can be had for under £1k
otherwise stick to GTI stoppers.
