shower base and sink- building a camper van

hi there

I have got an old Toyota Hiace Commuter, ex hostel bus and I am
building camping usable freaky furniture inside.

Was wondering if somebody knows, where to get a solution for:

kitchen sink, have a plastic box in a hole of a timber board, will drill a hole for water release. where get I something, cheap, to connect a hose to that hole.

Shower base/tray, I am looking for a cheap base, about 500x500mm, I know its small, but it should suit backpackers.

90cm bed frame, I like to give a third person a bed, hinge-attached on one side above the windows. Where could I find a metal bed frame that small, and cheap?

any info appreciated

thanks