I would get a built-in petrol generator. My truck uses diesel, but it's much easier to carry around cans of petrol and fill stuff with petrol out of a can vs diesel which seems to always get all over everything. I have used portables on my TT and they are a pain to use, usually loud since they are out in the open unless you put them in your rig, and then their tanks are so small you are filling them often.
A Propane generator runs approx 20% less efficient than gas, so it's going to suck down propane unless you size it 20% larger than it should be...at which point it will still suck down propane.
I enjoy watching full timers on youtube and it seems that people have good luck with solar and lithium batteries. Apparently they can run quite a bit with a decent setup, including AC. If I was going to full time, I would do some deep research into this setup.
