I will now more-or-less paste what I sent to our family friend who will be making the cabinets for us. Comments are definitely welcome, nothing is set in stone.

At least I hope for some planning their interiors this will be helpful in terms of ideas or dimensions. Drawings were made by me using LibreCAD, obviously accounting for various things we want to put away and where we want them to be located as well as the fact we have the additional "paramedic" door.
Layers for the upcoming drawings:
0 is the base drawing of the available space, and the wheel wells (which obviously jut up into the available space).
1Frame - the cabinet frame.
2Sleeping/solid - outward panels which are not openable.
3Doors - the fronts of the access doors.
4Drawer - the fronts of the drawers.
5Blocks - blocks which will run the length of the cabinets (front to back of the interior) and support the “sleeping top” which spans the aisle.
6Countertop - countertop on the right-hand-side cabinets.
7L-Track - depicts the airline-rail attachments which will also run the length of the cabinets. (
L-Track System | L-Track Tie Downs | Airline Track & Straps | USCC - https://www.uscargocontrol.com/collections/airline-straps-hardware)
Misc:
Door opening - working layer, depicting the upper limit of the opening of the third door for later purposes.
Fridge - an illustration of where the fridge will stand, which will later form part of the sleeping structure.
Interior of the Troopy looking from the top, left side is barn doors, right side is the seats.
2Sleeping forms the top of the cabinets. The shaded area is cannot be opened and provides structure.
2Sleeping - two hinged sections which allow access to the drawer below (left side) and open storage cavity (right side), two sections hinged to the wall for access to table (centre) and heavy recovery/emergency gear (right).
3Doors - doors covering the storage cavities, secured by magnets.
4Drawer - front of the drawer, which will extend up to the centre support of the sleeping area.
Cabinets looking in from the back (open barn doors).
2Sleeping/solid - the sheet that is illustrated vertically between the pink block and the grey l-track is perfectly measured to fit between and span the left- and right-hand sides of the cabinets to extend the sleeping space over the “aisle”. This would be held in place by countersunk magnets to the structure of the cabinets. There would be two pieces, each 1m long.
3Doors - front of the storage compartment doors as explained above
4Drawer - front of the drawer as explained above.
5Blocks - I have assumed a 1” x 1” block will be enough to support the weight. The section of the sleeping top which is closer to the drivers’ seats would sit partially on the
Fridge. The
Blocks should stop running before reaching the
Fridge since the fridge will support the sleeping weight and is at exactly the same height as the preceding blocks.
7L-track - profile of the L-track
Drivers' side cabinets (right hand side, since RHD vehicle).
0 - the line represents the wheel well, which will have to be accounted for in the structure.
3Doors (hinged) - the two smaller doors should be hinged on the left, and the large rectangular door hinged downwards
3Doors (magnet) - same procedure as above, the doors will sit behind the L-track.
4Drawers - two large drawers using the available space here
6Countertop - We would like the countertop to follow the contours of the available space, the only curved feature on this build.
7L-track - for reference, the size and location of the L-track.
Of further note is the angled section (depicted with a dotted green line), which will also be accessible from the outside when the door is opened.
Materials:
We would like to use baltic birch plywood. While I know generally cabinets are constructed from 3/4” plywood, weight is an important consideration for the vehicle and for these purposes 1/2” (general use) and 5/8” (particularly the sleeping platform) plywood work fine from overall knowledge & experience.
For the countertop, we would like to use some solid, warm wood, tbd but likely oak.
Hardware:
Hinges:
For the sleeping platform:
Concealed Lid Hinges - Lee Valley Tools - https://www.leevalley.com/en-ca/shop/hardware/hinges/40647-concealed-lid-hinges?item=00H5401
For the hinged cabinet doors:
Four-Way 175° Hinges - Lee Valley Tools - https://www.leevalley.com/en-ca/shop/hardware/hinges/cabinet-door/40980-four-way-175-hinges?item=00H6301
Latches:
For the drawers and cabinet doors:
Push-to-Close Latch, Small Size, No Restriction, 1 - 21mm (.04 - .83 in) Door thickness, 23mm (.91 in) Grip, 316 Stainless Steel, Electropolished - https://southco.com/en_any_int/m1-15-61-8
For the sleeping area:
Push-to-Close Latch, Large Size, No Restriction, 12 - 22mm (.475 - . 875in) Door thickness, 20mm (.75 in) Grip, 316 Stainless Steel, Electropolished - https://southco.com/en_any_int/m1-25-62-18
Slides:
For the largest drawer (located under the sleeping platform) we would like to use a heavy-duty lockable slide, something along the lines of the below, which would also mean no latches are required.
Double-Locking Extra-Heavy-Duty Slides - Lee Valley Tools - https://www.leevalley.com/en-ca/shop/hardware/slides/side-mount/58870-double-locking-extra-heavy-duty-slides?item=02K4718
36 inch Black Locking Drawer Slides, Heavy Duty, Full Extension, S1760L-36-BK - https://www.ovisonline.com/36-Locking-Heavy-Duty-Drawer-Slides-Black-P2742.aspx
https://www.accuride.com/en-ca/products/drawer-slides/heavy-duty-slides?filter=|length-782
For the other two drawers (in the right-hand-side cabinet), hold-out slides would be required, such as:
100 lb Hold-Out Slides (Full Extension) - Lee Valley Tools - https://www.leevalley.com/en-ca/shop/hardware/slides/side-mount/52491-100-lb-hold-out-slides-full-extension?item=02K4414
Mounting
The vehicle has a vinyl coin floor glued onto a plywood sheet, providing a possibility for securement to the floor. The walls (“door cards") of the vehicle are aluminum sheet and can be screwed into as well. For mounting of the sleeping area onto the wall, a block similar to the one used for spanning the aisle can be used.