After nearly having a heart attack when I saw how much the local caravan centre wanted for stainless steel sinks/wash basins (£40!) I spotted some virtually identical stainless steel mixing bowels in Morrisons for only £1.99!! So I bought one and simply drilled a hole in the bottom for the plug hole. Hope this is some help to people considering doing their own camper/dayvan conversion; I'll put some photos on here soon to show how mines coming along.
Cheers for now!