Welcome aboard from another 'over 40' member, however I've been driving GTI's since I was a teenager!
I've had an ST3 for over a year now and touch wood it's been fine and does the job. Makes the car drive how it should from the factory.
As for wheels, well there's so much choice, but as above, Greenouse's black Monza IIs look fantastic. I'm guessing yours is sat on standard 17s? I think Monza IIs are hard to beat style-wise for the mk5 and probably why VW have kept them on for the mk5.5 mk6, just try and find a set that are either cheap to do a custom re-furb or mint as they suffer big finish problems.