Just to give new self builders ideas, some pictures of my first conversion, this was a cross between a Citroen Relay and a Baily Pageant caravan. It served us well as a 3 berth for 6 years, till our youngest daughter went to Uni.
That has to be one of the best van conversions I have seen using a donor caravan and I wouldn't mind betting that it would sell quite quickly when the time came to change.