So tonight i managed to stumble across a compilation of links to some well known areas on the web that might be of benefit to you if you should ever desire to build your own camper.
These links are to composite panels and other similar type material manufacturers/dealers based in the United States that could very easily be used for the flooring, walls and the overall camper build structure.
and of course Nida Core, the panels which i have chosen to use in my build. These can be purchased off the following website Apdmro 3M
Perhaps you might find this list beneficial.