Earthroamer are poseurs. Air springs fail often overlanding. Sumo Rebel springs are the ''new thing '' for Tacoma's and F250's. For bigger camper trucks like an F550, you'll need custom springs made, maybe.
Bead locks are bad news. Good for wheelers, terrible idea for a pickup that hauls and travels. Instead of worrying about unseated beads, just learn to reseat the bead. Big full time campers should have two spares anyways.
If you want to go hardcore: a Ford F550 or Ram 5500 with super single brush truck wheels and tires will do well. Look towards Bundutec for a flatbed camper tray box. For permanently mounted camper boxes, I never recommend a cabover bed like a slide in camper. The box, should just be a box. Even minor engine repairs require removal of the trucks cab. Auto engineers are aresholes.
If you're going down minor dirt roads, and planning tons of highway, then a box stock F550 crew cab 4x4 will work perfectly. My box stock DRW truck has gone everywhere my Overlanding F250 has on 35's. Even with smallish towing and hauling friendly tires, the DRW's do well off road. The pro's don't get lift kits and giant tires for their work trucks and make it down pole lines and gas lines just fine. Remember, the more off roady, the less capable on the highway. My box stock Ram 350 DRW will haul a camper box at 80mph all day long.
Pretty sure that Detroit lockers are available for the F550's, you have to research that on your own. Lockers front and rear will help more than huge tires, lifts, etc.
Look again at pickup diesel reliability. They're very junky right now. I strongly recommend, as a master technician, that you look at Fords gasoline big block 7.3l with 4.30 or better axle ratio. And the gas truck is 1000# lighter.
Also consider an an LMTV from Acela. They're slow, but overlanding is about avoiding the highways for most of us. Absurd reliability, but it's a military truck that comes with it's own issues. Slow, loud, no AC, not a luxury vehicle, $5000 tires.