What should I get?

[Gabor Jacques <neotek@virgin.net>]

I am about to sell my 92 80Q 2.8L (90Q for those in the States) and want
another quattro. I am not sure whether to go for a late S2 (coupe with
20V turbo) or 2.8 A4 Q. The S2 will allow for lots of performance
upgrade potential but is an older car with the potential of expensive
maintenance waiting around the corner. On the other hand the A4's 2.8
does not allow for much performance increase and being younger should
last longer before any expensive maintenance is required. I must admit
part of the reason for selling my 80Q is that it's too slow, the other
is that with 124K it's becoming expensive to maintain.
What should I be looking out for on the S2 engine to be sure I don't end
up with an abused engine?
I would appreciate any comments.

Regards