Anyway, does anybody have any sudgestions as to what to do to make it look better, more special, more GTI? I am on a tight budget also.
Don't sweat about it... The Mk4's all about subtley anyway. Back when they were new, it was the "gentlemans hot hatch" as opposed to a lairy type-r for example.
Chris has got the right idea above - you need a set of the better rims to get it looking special, but I would REALLY suggest (IMO) sticking to genuine VW alloys as the Mk4 is approaching the price level where its becomming affordable by chavs (higher mileage ones anyway), and the first thing they do is stick a set of fox alloys on them.

PS... And if you put some audi alloys on it, my head will explode (seen TOOOO many lately).