The earlier versions had a bigger turbo (1992-1994). The later version was more refined and had a smaller turbo(1994-1997). They are simply categorised into big and small turbo.

The small turbo is recognised to be more driveable and has a quicker 0-60 as standard but the big turbo is easier to modify and offers more tuning potential. Looks wise they're pretty much the same.

I know of a really nice Ash black one and mint Mallard green one.