With a gas engine I would definitely go with the 4.10 gears but with the diesel the 3.42 should be fine. Even with a gas engine and the 3.42 the tow rating is around 10,000 lbs. and your camper and boat trailer are in the ballpark.
With a diesel engine the GCWR is over 30,000 lbs. and subtracting the weight of the truck leaves 22,000 lbs. for the camper, boat and trailer, passengers, and gear. Figure 15,000 lbs. for the boat, trailer, passengers, camper, and gear, and you are not even close to the capacity of the truck.
The 4.10 would make sense if you planned to tow a 20,000 lb. horse trailer otherwise it provides no real benefit according to the manufacturers towing specs for what you have specified as the total load weights.
The concern is the load on the rear wheels with the passenger, camper, and tongue weight combination. The tow load is incidental.