A few years ago we upgraded our tow rig to match a 31' 7,600 GVWR travel trailer. Being a bit uneducated (i.e. payload) and pressed for time to get a new rig, I started with a 2016 Ram Power Wagon. Plenty of power, fun to drive when not towing. The payload and range quickly became an issue for long trips (over 250-500 miles with some being several thousand mile trips out west). I then errored on the side of overkill and moved up to a 2017 Ram 3500 SRW with a HO/Aisin 6.7 with the automatic level rear air suspension and an 8ft bed.
-Auto leveling air is awesome for hooking up and towing a lot being able to adjust the height of the truck with a push of a button and never have any rear sag
-8 ft bed is a game changer for hauling gear, mountain bikes, firewood, generator, cooler, etc
The thought process was to have ample payload, range, cargo and carrying capacity for our family and all gear and be able to have a truck that could pull camper and have enough payload to handle a different setup (truck camper, fifth wheel, heavier camper).
-The HO/Aisin is a stout combination but the trade off is fuel mileage. I don't mind the firm shifts.
-The HO tuning and lower compression ratio over the SO Cummins yields towing mileage of 11-12 MPG and unloaded/not towing highway mileage of 16-18.
-The SO Cummins will deliver better mileage due to the tuning and higher compression ratio.
The issues I have had with the truck have all been tied to emission components. Failed EGR Cooler at 72k miles (replaced under Certified Used warranty within 3k of ownership). EGR Valve check engine light. I would advise you to purchase what you can afford to acquire and maintain and consider range as a factor. If your trips and travels are all within a few hundred miles, the gas 3/4 or 1 ton trucks (or F150 with heavy duty payload package) will do the trick especially with the 8 and 10 speed transmissions. However, 500 miles in a day behind a modern diesel is a joy. They pull without breaking a sweat and do it all day between 1,500 and 2,200 rpms which is very comfortable