Been looking for a while now myself as i've had my a2 1.4 SE for a good couple of months, the best thing i've found for new rims and kits is the audi accessories site but, and there is a but, it's not bloody cheap! Other than that i did find one german site that used to stock the one and only company that made a sportier kit for the a2 but they've stop manufacturing the kit due to lack of demand! As for rims, if i was you i wouldn't go any bigger than 17's, at least you know audi as standard do go up to 17's but once you start going bigger you've got to think about the wheel arches rubbing, etc. Here's the link for the audi site:
http://www.audiaccessories.co.uk/(ilwx4oec...es.aspx?model=1
Oh and a good example of that audi sports kit is here:
http://www.*********/gallery/browseim...=3&userid=2331
I'd check out teh audi rims on the accessories site cause i absolutely love them but they're pretty pricey for my liking!
Hope this helps guys, not been on this forum for a long time, guess i best have a mooch around!
Mike