With a gas engine it is important to get 4.10 gears for heavy hauling and or towing. I have always had to special order American trucks and SUV's to get these gears. Only Toyota puts low gears standard on their 4WD trucks.
You need DRW to support the load of a very heavy camper. 4 tires rated at 3,000 lbs. per tire will support 11,000 lbs. (the limiting factor becoming the axle and wheel bearings) and subtracting 3500 lbs. of truck weight at the rear axle that leaves capacity for 7500 lbs. of camper. With SRW the best you can do is go to 19.5 rims and tires with a total tire load capacity of around 8800 lbs. or about 5300 payload maximum.
Take the published camper weight by the manufacturer and add 400 lbs. to get a true dry weight and then add 1000 lbs. to get a ballpark number for the likely load the truck will be hauling. With a trailer you then need to add in the weight of the weight distributing hitch, the stinger or extension, and the tongue weight of the trailer. What is borderline with SRW is not a problem with the additional 2 tires with DRW.
AS to DRW this also puts more stress on the truck frame and I know if I was buying a new truck with DRW it would be either a Ram or a GM truck with their much stronger frames, and definitely not the current Ford F-350 trucks. I know there are many who identify with a particular truck but I have owned trucks from Reo, Willys, Dodge, Ford, Toyota, and GM, and I buy whatever happens to be the best at the time. Blind brand loyalty is stupid to put it kindly.
