Remember that payload is without people so it is not huge. General rule of thumb is to add 800-1,000 pounds to the camper dry weight to get a better approximation of what you will be putting on the truck.
I went with a gasser to avoid the added weight of the diesel engine. Folks go both ways on gas versus diesel. You also really need to see the door sticker on the truck to know the payload. The weights you find online are before options on the truck and in some cases you will be shocked how much you lose there. On my F350 it was several hundred pounds from the online spec sheet to my door sticker.
Steve and Andra
2012 F350 6.2 gasser SRW LB
Fab Fours front and rear in case we run into a rhino
2019 Northstar Laredo SC