It depends on what you want to do with the said cars. If you want to keep thing pure, and not f"@'k about with it then S1 all the way!
BUT, if you are serial modifier and just wanna make things faster and flashier then it has to be the S2!
Personally I would love to own a S1, but then I would also fancy an Escos, TVR Tuscan, a 3 Door Sierra - the list goes on!
So I have to make do with what ive got - a wicked little H reg XR3i - does me fine