www.factorybacking.com does GasGas in any design you see on there site. They told me in an email they do them they just don't have big demand and no section in the site for it. Looks like pretty good prices too?
I have found 2 other companies that will make anything you want for the Gasgas too. I have a Bike Graphix kit and Hygh Octane in Indiana will do full custom kits for around $200