Everyone is going to have a different opinion. Here's mine: I have a 2015 F350 dually with a 4300 lbs camper. If yours is 4WD, I would put outside-the-frame mount airbags, plumbed separately (dual path). Then add the Hellwig Bigwig sway bars front and rear, and Rancho 9000 shocks. The shocks and airbags will let you adjust the rear height to keep the headlights on the road, the 9000 shocks let you adjust the dampening between loaded and empty. The (much) larger sway bars will eliminate body roll empty and with the 5th, and minimize it with the camper. Since the airbags will be carrying some of the weight, outside-the-frame versions will maintain the same roll stiffness as the springs.
If 2WD, getting airbags to fit properly is difficult because of the lower ride height - I did it on my '99 but had to modify the mounts and though it worked it limited suspension travel.
