This is my layout sketched onto the Sportsmobile template for a Promaster 136" wheelbase. Ignore their square wheel well enclosures. Mine are angled. The drawing also shows a shallow counter, but it is actually 21" deep because it goes into the window well.
The permanent bed covers the 4' X 6'+ area to the rear. The bed board is at 28", so with a 4" mattress and bedding, the bed is still visually under the windows (Motion Windows), which are maximum for the openings. The head of the bed is easily articulated for reading in bed. The storage above the wheel wells is accessed by lifting the ends of the bed, thus the storage at the foot of the bed is "deep storage" of lesser used items, extras, and souvenirs. Storage at the head of the bed is drinks and fuel. Boots sit on low shelves beside the slider. A charging station is above them.
The area under the bed is total storage. Ten 28"-deep drawers face the interior. The "tunnel" on the passenger side holds full packs, laundry, etc., closed off by the only door in the van.
Engel MT45 chest fridge lives under a counter-top lid with a large drawer underneath for fresh fruits/veggies and condiments. This drawer is generally cooler than ambient.
Tub is a non-plumbed 6"-deep steam table tray with 700W microwave and drawers underneath for utensils, electronic gadgets, ditties, water boiler and breakfast supplies.
Two Formica tables pull out from under the bed board at 28" high. Together, their surface is 29" X 29"; it is handy to be able to choose one or both or none for the large unobstructed area. They are supported by the shallow top drawers and thus quite sturdy with no legs. The split has never been an issue, nor have the exposed slides. We sit on the folding stools that store by the counter.