Hi mate. Just saw your video and plan sounds exciting!
I’ve just finished (nearly) my SWB t5.1 Caravelle swamper conversion. Started with a 7 seater bus very much like yours but with a 2 + 2 + 3 layout, and I’ve since had it pop topped through skyline, they have a specific mod for Caravelle and shuttles plus I’ve added a 200w solar panel on top. I’ve done full leisure battery system, all fitted under front seats with 100amp hour lithium, Victron DC to DC, smart solar controller, shunt and battery sense, diesel heater, 240v hookup with socket under bonnet, rusty lee swivel bases on both front seats and full tint all around. I also decided to have kitchen unit at the rear so I’ve built a Slidepod type unit at the back, which serves as part of my bed base. The top is the same height as my rear bench seat when it’s folded flat so I can fold that down, pull out a folding memory foam mattress that normally lives on top of the unit when travelling, and that gives me my downstairs, full width double bed, but I can still access my kitchen unit from the rear under the tailgate which has a compartment for my fridge, cooker, water etc.
the main difference with the Caravelle though is that you can easily remove the middle two seats so we only camp with 5 seats which leaves more room inside when bed is up, especially with front seats swivelled.
Personally, although it is a bit more work to accomplish, I think it makes the perfect all round van as I use it as my family daily driver with 7 seats when needed but with a couple of alterations it can then be a full camper with 5 seatbelts and sleeps 4.
I’ve got awning rails on both sides so I can have a full drive away awning one side, which provides extra sleeping space if needed, and a sun shade awning on the other side for alfresco dining etc.
I’ve done all of it myself except the pop top, solar, awning rails (had a local skyline approved guy do that) just from watching YT videos. I’ve gone with Tomahawk Kato’s on mine which look mint, plus side bars, bull bar, and a couple of extra styling tweaks.
I am considering remaking the kitchen unit to be more slide out instead of a drop down door but it works for now.
Good luck with yours!

https://photos.app.goo.gl/5S6o6a7ioSkbfr9XA