Originally Posted by GonneVille
Welcome to the Club!
Unfortunately, the aftermarket is very limited on the 92-95 cars. On the other hand, if you have a little skill with a Dremel tool, there are plenty of DIY mods that can net you decent gains.
This is incorrect. Every single aftermarket part available for the S2 is available for the S1 with the exception of an intercooler, and that'* coming along quite nicely.
The bottom line is that you don't need to upgrade any internals at all. A stock bottom-end rebuild is more than sturdy enough to support more power than you're ever likely to see.
Post in Performance and Brainstorming with your goals and realistic budget, and we'll help you get there.