I built a 1989 Chevrolet V3500. Has Alcan leafsprings on all four and factory bench seat. Comfortable on the long highway rides and off road. I started with a RTT but built my own camper box with queen size bed up top and a couch/twin below.
I have two 80 watt panels on my hood for the past 2 years and it has worked great. I can leave my fridge running all week without starting my truck. The heat on the hood doesn't matter since you are not using solar when your rig is running.
I tried balance beads and I wasn't happy with them and ended up removing them (what a pain). I just took mine to a local 4x4 shop and they balanced them the old way and am happy.
My beadlocks are DOT approved. But the shop would have done them either way.
I would check out 23ZERO and they are in your area. You can go to their show room and check it out. A hard shell will not work for that many people. With the 23ZERO and an annex will work for you for a lot of years.
I don't remember what @Everlanders did with his rear bumper. Are you going to make it an air tank? Truck looks great. Hopefully see it on the road in Oregon when you're done.
With you van being 2wd it isn't like you are going to driving trough a deep mud hole and since it will be mounted on the rear to get you out of something you pulled into not trough something so you should be able to get away with a smaller winch and carry a couple snatch blocks and a winch line...
Make sure you follow instructions. I bought a manufactured trailer and they installed a top and bottom plate so the panel had no where to expand when hot out and ended up popping the tape lose. Ended up screwing it all down.