what are the differences in widths and distance from the back of the cab.
I would be looking the develop a "pod" that can fit all/ most utes and make up front sections for the fridge of varying widths to allow for the different vehicle descrepancies.
Doing something like a pod arangement will allow you to sell to the dual cab market- make it fit these and then fridge/ storage boxes to fit the space cabs etc?
or are you still going down the vehicle and camper sold together?
my thoughts anyway