I think that is a brilliant idea, and to be honest, I'm suprised that no-one has done it sooner. To have all the critical dimensions for each variant of van, stored in a computer 3D model that your design software can utilise, would make planning and designing a breeze.
A CNC router would make short work of cutting all the furniture components needed - even if they were to one-off requirements.
One of the things that frustrated me when looking to convert my own van was the lack of options available. Loads of companies offering basically exactly the same thing. The only options being different veneers, colours etc. Everything all ends up looking the same with the same layouts used all the time.
Doing it your way, if a customer does not want a rock and roll bed for example you can still use your 3D model to suggest alternative layouts,bed positions and sizes, kitchen and cupboard sizes and shapes, that you will be able to guarantee will work, and all before you cut a thing.
I wish you all the best.
2011 SWB medium roof 2.2l Mk7 115 T300 in Frozen White. Stealth Camper converted.
"It's better to burn out, 'cause rust never sleeps..."