Dear kylesimpson--  Any good tire (or tyre) dealer can help you with this question.  Where I come from (where a tire is a tire), I might look at a website like www.tirerack.com.  If you come from somewhere else (where a tire is a tyre) you might like to check them out at www.etyres.co.uk.  The size you are looking for is 205/55-16.  I hope you find what you are looking for.   Good luck from Bovan.

I just had a set of Michelin pilot sport 2's fitted to my a4 2.5tdi quattro, and could not believe the difference it has made over the budget ones it had when i bought the car. expensive though (but worth it!)