I believe this problem is not only due to the wave-wear that semis do to the road surface, but possibly the combination of your speed and wheelbase and the distance between the expansion joints in the concrete road surface. Has anyone who had this problem on roads such as this experienced the same bounding effect when on an asphalt surfaced road at the same speed? When I was a kid, we travelled Highway 99 in the summer and it rode and felt like that due to the shortness of the concrete sections and the expansion joints crumbling under 80,000 lb. semis. The "fast lane" wasn't much better, but once off that road the problem went away....and this was in the family station wagon!
If of course, the suspension of your truck is lacking with the load/speeds you drive at then the problem would be worse on "bad" roads. My question is if it is necessary to go beyond the suspension upgrades an already maxed out truck has is worth the cost to fly down the highways when so little of those highway conditions exist and your time on them will be minimal.
I believe anytime you redesign the shock/spring/air-bag suspension on a vehicle it will end up either "riding like a truck" or "riding like Grandma's Buick" especially when on different surfaced highways and especially with the camper dismounted.
But....if you experience this problem all the time and at any speed over 55 then you already have suspension issues that need addressing! Comparing apples to oranges....different trucks, different campers, different road surfaces, different speeds, different suspension set-ups....all that can contribute to a "hard", "mushy", "bouncing effect" or an uneven set of the truck/camper once mounted in the truck bed.
Your results may vary....so don't just copy the other guy's rig without determining if you BOTH have "apples or oranges" so to speak!
Starting with a truck that can haul your camper and everything/everybody who will hit the road is the first order of business...trying to make the truck handle the camper and stuff is the wrong way to go but that's just my opinion...
Do your homework on what you want to carry...THEN find a truck that can handle it or you will be spending plenty of ca$h trying to "upgrade" the truck/suspension to handle it if you started off with a truck that wasn't cut out for your load.
Never send a boy to do a man's job....so they say.
Adding better shocks when yours die is one thing....having to add springs, air-bags, etc. right from the git-go indicates to me you bought "not enough truck" to begin with.