Dont get the ebay one its wrong and dangerous It has 2 single pole mcbs as the main switch this is very dangerous as the neutral could be isolated but not the live and it has no RCD protection You should have a 2 pole RCD as a main switch To comply with the regs you need 2 pole MCBs i would recormend in 6amp and 10amp
Took a few pics of my hook up install... Plug fitted under the van, the black flexible conduit clips into a fitting that screws into the rear of the hook-up socket, nice and secure. I ran the cable up through a hole that was already in the floor, I just had to drill a 22mm hole through my flooring from above. Consumer unit fitted into my bench seat / storage box, I then ran the same flexible conduit containing the mains cable feeding the doublesocket. Double socket fitted into ply bench seat using a drywall back box for general use, I plan to drop a single socket under the rock and roll bed for the ctek. I have some more of the conduit & the fittings & will bring them to tekenders if anyone is doing a hook-up and would like some...