3 things:
1) Most folks over load their trucks. Hence, all the interest in suspension mods on this forum. You want to stay well under your trucks GVWR WITHOUT suspension mods. You and your truck will be much happier.
2) Most campers stick out past the truck bed. On rough roads, this rear section gets blasted with sand, dirt, mud, water, etc. The rear over hang can contribute to ground clearance issues, and make it difficult or impossible to turn around in a tight space. Buy a camper that fits completely in the truck bed.
3) Folks here love their north-south queen beds. Forget about it. Those long cab overs will flex and fail with extended off road use. Get yourself an east-west bed.
What you want is, small, light, and mobile.
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(PS. Since that photo was taken, I've completely removed the four corner hydraulic jacks. This gives better clearance, and, shaved 124 pounds off the payload).