Here's the link to the 2010 Ford Towing Guide,
https://www.fleet.ford.com/showroom/...10_default.asp.
According to this Guide (#20), it appears that your crew cab has a Tow Rating of either 15,300# (4x4) or 15,800# (4x2). Keep in mind, however, that Tow Ratings are for a basic truck with no options, no gear, no passengers, a partial tank of fuel, and only one 150# driver. Once you start adding all these things to your truck, what your truck can tow without exceeding any of the ratings will be something less.
I would recommend that you load up your truck like it would be for any trip, with a full tank of fuel, you and your wife, and all the "stuff" you'll carry in both the cab and the bed of the truck, including the fifth wheel hitch (which, being a short bed, I hope you got a sliding hitch). Now take you and your truck down to the local scales and get it weighed.
Once you have the actual "real life" weight of your truck loaded for a trip, subtract that weight from the truck's GCWR (23,000# according to the Guide). The difference will give you the MAXIMUM loaded weight of any fifth wheel you should be pulling.
Now subtract the actual weight of the loaded truck from its GVWR (anywhere from 9,200# to 9,600# depending on wheelbase and whether or not it's a 4x2 or a 4x4...see #12 in the Guide). The difference will give you the MAXIMUM hitch weight your truck should be carrying.
You might also want to get that fifth wheel weighed...I'd be willing to bet money that in "real life" it weighs more than the 11,390# published dry weight because that figure doesn't include any manufacturer-added or dealer-added options. By the same token, that 2,110# hitch weight won't be the actual hitch weight once you get your fifth wheel all loaded up...it will be something more (and this is likely to be the weak point of your 3/4-ton truck; i.e., you'll reach the GVWR before you bump up next to the GCWR).
While "beefing" up the suspension will help with the ride, it will do nothing about changing any of the numbers.