Welcome Yantos
I have a bog standard Clubsport too which came on 18’s which I subsequently “upgraded” to 19’s. Suspension wise it feels much like my former Ed40 Clubsport in daily use, which is no bad thing.
Pretorias will fit straight on perfectly.
You don’t need DCC as the car rides and handles perfectly well on standard passive suspension.
Go for Pilot Sport 4S tyres as they work really well on Golfs, or Goodyear Assy 5’s will be just as good I’d imagine.
If you want genuine VW wheels you’ll have to keep an eye on eBay (German VW dealers usually) or forum/social media classifieds as UK dealer prices are truly eye watering.
Personally I went for replicas which weigh the same, give or take, as VW wheels plus still use the original bolts and bolt caps. Centre caps being the only slight issue as regards to using OEM parts.
CMWheels seem to be the go to place for reps, they’ll normally offer a slight forum discount too.
Crossed with Guzzle’s post as I was typing so some stuff duplicated.