Advice to date concerning the canvas back is that it's complicated to erect. Is that the case or just a familiarisation thing?
The Canvas is not designed to put up and down every day, not so much complicated as it is straight forward but very time consuming, I allow 2 hours to fully erect the tent on my workshop and/or workshop trailer (same tent) and it's a two person job to lift the legs of the frame up into position as it needs to be lifted about 18" .
So lift up frame, extend frame out the back, roll canvas out the back, untuck inverted canvas on sides, put up heavy wooden posts and guy ropes x 4, put spacer/tensioner bars in place, put draft skirt around tray, put 7 wall panels on and latch lace together.........
I've done the simpson in a modern 4WD and slept in swags it's the best way to do it, less than 2 minutes and set up.
I'd still buy the workshop as they are fantastic vehicles and would be great going through the Simpson or anywhere....
Juddy's idea is good but you can't raise the frame, you could sleep in the back OK (tray is two short for me and I'd get cold feet) or for storage
Hope this helps
Scott