hiace camper out of gaz

hello,does anyone know where i can get campingaz cartridges cv-450. in the uk.my hiace camper has a handy gizmo that automaticly switchs to a spare cartridge when one is empty.great if i lived in japan,or even australia,but can i find this size in the uk????? well perhaps someone can help.otherwise guess the little handy gizmo things gonna get the boot,and i,ll fit the bog standard one tank joby.

http://www.singersoutdoors.co.uk/productpages/gas-and-other-fuel/camping-gaz-cv-470-gas-cartridge.asp

Any good?