Since we did this very rough prototype vid a year ago, we switched to a linear glide rail and car system from our framing vendor to make the bench/bed work. We're using that system for the cot extension in our FJ Cruiser Stealth Camper along with a spring-loaded plunger to hold the cot extension in place while we are driving. The hinge and framing part of our solution remains unchanged.
Haven't started building the furniture yet because I don't have the van yet. Transit Trail on order. You can see the design work here: www.EigerVans.com.
And then we switched gears again and decided to buy a FJ instead of the Trail. Saved over $40K and gained a tremendous amount of off road capability. Our camper design for it still has two separate beds, but of course lacks all the nice interior lounge space you get with a van.