Thinking of buying S4. Any advice??

I have been looking for a 2000-2001 Audi S4 and am ready to buy. Can you guys help me out on what potential issues to look for?
The ones i'm looking at all have roughly around 80k on them so I know the timing belt is an important thing. Besides that I am not aware of anything. Do they have any chronic issues? any weak parts, I have to make sure are in good working order?
Also, if they're well taken care of what can I expect out of that engine and tranny? Do the turbos usually have to be replaced on those?

Thanks a lot for your guys help!

I Wouldn't waste my time/money on an Auto one. I was gonna buy a Auto S4 and i drove it and liked it then drove a 6spd one the next day and all i have to say is 6spd FTW!

UHm The waterpump seems to be a problem on the car so you might want to get that replaced. Like you said the timing belt is a big one for the 80-120K mile S4's And depending on how hard the S4 was driven in the past will determine how long the stock turbos have. My buddies S4 Stockers went out at 78K (previous owner musta pounded the hell outta the car) I've seen some at 130K on stockers so it depends on how bad it was beat. Uh the CV Boots/Wheel bearings seem to go out on them every so often as well. Other then that just your typical 80,000+ Mileage shit that goes bad.Also seeing how you most likely want a 6spd i wouldn't rely on the clutch to last you much more then 20K miles. any more info just ask me or go to Audi Zine DOT com

Edit - I just saw you ask what you can expect out of the motors. I've seen them RUN FOR EVER some with 200K + Miles. so you should be worried. I've seen 400WHP on these Pretty easy all day long after about 500-600WHP your gonna need to look into some engine parts (rods/pistons) And some drive line upgrades so you don't leave your differential parts at intersections lol.

The main problem I've seen with S4's are oil leaks from the valve covers. You'll notice it when it leaks. Cuz when it rains......It poors.

i'd agree with the 6spd.
my audi isnt an A4 for mines a 93 and the engine runs great..i have ~120k+ miles on mine. runs like a charm. I wouldnt be worried with the engine...every engine will have some problems one way or another.

This should help you.

Link (http://www.audi-sport.net/vb/downloads/Audi_S4_Buyers_Guide.pdf)