You are asking for a quad - but many, many parts are interchange-able between the enduros and the quads...
In the U.S., there are several GasGas Riders Club sponsors that have on-line ordering and one has an extensive e-bay store.
Gofasters deserves alot of credit for providing an extensive on-line store AND
on-line oem parts fiches. In addition,
North Tahoe Motorsports has a large listing of parts in their
e-bay store.
jeff
webmaster
GasGas Riders Club
p.s. The underlined items above are links to the webpages for these items.