well, re ABS , although I'd rather live without it, I dont think its crap , as the standard 33 brakes are weak !
Regarding the fuel tank, ... so what ? how often do you need to replace your fuel tank anyway ? Even if its rusted and leaking, it can be fixed very easily
Exhaust systems are still available both for standard S3 33's as well as for the P4's.
I have 2 33's myself ! One is 1.8 16v and the otherone used to be a 1.7 16v and now has the engine of the 1.5 8v.
I drove the P4 once and although it is slower than my 16v 33's, I must say its much more fun to drive around fast corners !
Its something special, something not everybody has.
Even so, whatever you choose to buy, I'm sure it will be worth it