Payload is certainly a consideration. Tires and suspension (shocks and springs) are a big part of the payload limitations. Diesel, Power Wagons have the payload about equal to a standard 1/2 ton due to the weight of the powertrain and softer springs, respectively. Most diesel 3/4 tons are going to be pushing that payload with a standard 5er, but
there are some nice 1/2 ton towables that give the advantages of the 5th wheel with a lesser weight. But you likely can get a larger travel trailer than a 5er, which based on your conditions of use, might be a better plan. You typically lose storage, auto-level, compartments for propane and batteries, but they do tow nicely with the 2500s up to about 10K.
The KZ Durango Half-Ton models are well built and should be in your ranges.
https://www.kz-rv.com/products/durango-half-ton-fifth-wheels/floorplans.html
I used airbags on the 1/2 ton Longhorn, and they were okay, but after a few years, slow leaks, I opted to change out the bump stops to a polymer progressive. When folks are near the limits, it is a good option to keep the truck level, mitigate porpoising and wag.
https://timbren.com/collections/timbren-ses
We've spent 110 days so far in our 28 month old Cruiser Aire. The 1/2 ton towed it fine, and it has been really good for us. That said, one of the reasons for the 2500 gasser was to be able to move to a 5th wheel under 35 feet long in the future. You have enough truck for a good number of RVs, you will just have to go to some lots and RV shows to see which ones appeal to you. Or, do a RV rental on one you like for a weekend and live in it. Before we bought our Cruiser, we went and visited it 3 times. We even took a sack lunch and the pups (salesman was great, service dept sucked) and spent about 4 hours in it one evening.