I would say ebay is the best bet for a set of Classix's, I'm also looking for a set, they seem to be fetching about £400 a set on ebay, but it is dependant on the condition of the wheels and tyres.
Personally I'm not a fan of the Madras wheels on a MK5, I think they look better on the Passat. (From what I can remeber they are quite a 'rare' wheel, I think they were only ever fitted to the W8 Passat, but I may be wrong?).
Cheers
Chris
MK4 has gone...Mk5 has arrived!!