I have a tinted Zero gravity one - but never shifted it as its tinted, great quality and fit though and I can recommend them:
I got mine from TTS performance who I remeber being very fast...
http://www.tts-performance.com/catal...821f801fdbaa5e (they now have the ZG double bubble screens as well) as do....
http://www.sportsbikeshop.co.uk/moto...ontent_cat/278 possible opions include
Powerbronze
Skidmarks
Frank