You didn't state whether the truck will be gas or diesel powered - an important detail!
That makes a difference when it comes to truck's actual payload.
If the truck has the heavier diesel engine, you will find that the truck with camper will exceed it's rated GVWR capacity.
Either way, the truck will "handle fine" if you add adjustable shocks such as Rancho 9000's. You might want air bags as well to help level it out.
If you have the diesel engine and the AF 1150 - it will be overloaded by a lot!
If you are not comfortable with that, then the 990 would be a more prudent purchase.