I really don't know a lot on this subject but check out the Cooper Zeon LTZ. They also make a 275/45/20 and it seems like a great tire.
20x10.5 et45 275/45/20 Cooper Zeon LTZ H&R springs - Club Touareg Forums
20x10.5 et45 275/45/20 Cooper Zeon LTZ H&R springs - Club Touareg Forums