I have a 2000 1.8T Quattro Tip A4 Avant. I have 144k on it right now. Only work I've done is a wheel bearing, which they are supposed to be notorious for. There are eight ball joints in the front, but they are attached to the eight control arms :lol:. I would make sure that you have a timing belt receipt, or expect to replace it. Also, find out if they run a full synthetic in it; there are a lot of issues with sludging if the oil isn't taken care of. The only other issues I have with mine is the secondary air pump went bad, so I have a permanent CEL since I haven't gotten around to replacing it, and I have an engine mount that's leaked (easy to identify by pink fluid on the belly pan).
If you need any work done, or if you want a knowledgable mechanic to look it over, I would highly recommend Stefan at GMW (
http://www.gmwwaterford.com/).
Also, no pictures so I'm not sure, but typically what non-Audi people (myself included) think is leather in these cars is a fake leather called leatherette. I think you can identify an Audi with the sport suspension by the three spoke steering wheel as well.
I'm in FH as well and I have a VAG-COM, although the laptop it's on is a bit flakey. If it has a CEL let me know and I can try to pull the codes.
Personally, the Audi is a pretty nice DD. Handles well in the snow and has ass warmers in it, and heated mirrors. Worst part is all of these little things that spoil you - you won't be able to go back to a 'normal' DD again without them.