250-500cc 2000 WR360 Gas Cap Replacement

Anybody have a preference for a gas cap, the one I have the piece sticking up for venting is broken and the thing flows fuel all over me everytime I have a full tank and I decide to take a small jump, so my gas mileage is sucking. It also is leaking around the neck. Looks like the gasket has a small cut in it now. Don't know how that happened.

I have seen some billet ones with the little valves on top, but I have been unable to find one.

ikon racing do i billet on, i went on the bay and got a non return valve for a gas gas the only niggle is it doesnt allow heat expansion for gas to escape so the tank swells. the valve was £3 and the cap aroud 20

good luck