I have a similar setup, but didn't have enough payload to be "legal". The 1172 weighs in around 4550 lbs, wet (but without gear). The truck was 8220 when I last weighed it by itself. (see my signature for exacts) but 4x4, long bed, DRW.
As of last week:
My truck & wet camper total weight now is 12,860. I had a spring shop add upgraded 2000# springs to the vehicle, bringing my GWVR to 12,870. (10 lbs, woo!)
When I add all of my gear (I had most of it in the camper already), wife, dog, I should be up around ~13,100.
With the upgraded springs, no sway bars, it rides great. Sway Bars are being installed tomorrow just to make certain.
2008 Silverado 3500HD, EFI Live!, Additional Leaf Springs, Big Wig Front and Rear Sway Bars, Torklift Mounts & Tiedowns, Firestone HT 245/75R17, APE Intake, & Uniden BC536HP
Running with 2014 Lance 1172, Solar, Added Inverter
The Truck Camping Map Project