I am going to revive this thread because I think my MJ is soon to become more of an overland type rig. I plan to run a topper with a roof rack, where I would mount my "water heater" (black PVC as previously mentioned). I think I would also run deep-cycle batteries to run lights on/in the topper, something to have pressurized water, and maybe an outlet or two. I also think I would want to run some sort of U-shaped shower curtain and a shower head off of the black PVC for showing. I probably have a slide out grill/cooking area that would come out from under the bed platform. I would also have black curtains that go over the topper windows with Velcro.
@Pete M, you could make another MJ trailer that is just for camping with one of your many beds and then use your current trailer as a, well, trailer.