The GTI 16V BBS wheels are 15x6.5", and are sortof a 2-piece wheel. They have a center cap that covers the lug nuts. The GLI 16V BBS wheels are 15x6", and one-piece with exposed lugnuts. In my experience, the GLI BBSs have shown to be a bit stronger(read: resistant to potholes). They are also a better looking wheel, IMHO.
So far as tires go, I'd run 1 195/50-15. I like the Yokohama AVS Intermediates, and a ~$50 each in that size for a *nice* Z-rated tire, you can't go wrong. HTH -Dave '91 Jetta GTX 16V '88 Jetta GLI 16V '84 Vanagon
