Hurdy uses the hollow Autotech Lightweight ones.
Some people use the Eibachs, I think Robin....
I've been told that H&R make a very very good set of anti roll bars for the GTI, and they will be my choice in a couple of months
Although, my tuner (Tuningwerkes) says that the H&R ARBS are the best, but there is not much between them and the Eibach ones in the real world