18's just dont look right on the G because the tires required are too thick.

Have you considered Work VS-XX? you can get those in 19" and they look almost the same as the GTU. Ravspec is having a special on them right now for a lot less than the volks.

 

I'll be different and vote for the SF-Challenge. I love 5-spokes, but not usually a fan of mesh-style. The GTU's are one of the few that look pretty good though.