I agree with Derek as long as you have "E" rated tires that are rated at 3200lbs ea, AirBags, and a EB of some kind. A small power chip of some kind won't hurt either.
I could see a trailer in the 35' range with a pin weight no more than 2500lbish, and a total ready to go trailer weight of 14,000lbs.

I have all the above mods, and I pull a 40ft trailer with 2900lbs of PW and a total GVW of 14.5Klbs. I do it, but I'd like just a little more truck under me.

 

The tires are your weak link, you have got to keep on top of them or you will lose one or both if SRW. The DRW gives a bit of safety margin but still it is critical to take care of your tires. Duals that have sidewalls touching with or without a load are looking for a place to blow out.

The three biggest things to think about with your 5er weight is TIRES, TIRES, and TIRES.

 

Close to 21K in weight here when completely loaded to the gills. Of course my 3500 is far from stock. Still would like a exhaust brake.

 

If you're asking for suggestions, look at a Crossroads Cruiser CF30SK...33.5 ft, triple slide, all plywood (no OSB or particle board), aluminum frame, full size queen bed and private bath (not open to bedroom), 8K +/- dry weight.
We surely love ours. Check outwww.crossroadsrv.com/forum/default.asp.
Good people will give you honest opinions.

 

I pull a 34' Mckenzie Starwood (3 slides) with a totally stock 05 2500 quad cab short bed with AT. Truck is rated to pull 13400 with 2540 tongue weight. There are 1000,s of 5th wheels to pick from that weight less then that. The truck does a very good job of pulling the load and gets around 14 MPG doing it. That includes pulling the Rocky's several times and the Pocono's twice. I am getting ready to add Blesteins in an effort to improve unloaded ride.

 

My DW and I started to camp again and I wanted a 5er which will pull better and I believe easier to back-up. I did all my research on the net and found two good sites, one is http://www. rv.net.com and the other is http://www.rvadvice.com ( I do not know if I can list these but I did and sorry if I am wrong for doing this). I believe there is a listing for max GCVW and GVW of all makes and years, in one of these sites. You may need to do a little research in the sites to find the information. Also find a good small dealer, sells only one brand or two. He may not give you the best deal you can get from a mega store but he is relying on repeats for his lively hood. Just my $0.02

 

I have a 27ft 8000lb loaded to camp , my truck laughs at this weight. I'm going around 30-32 next time to give me a reason to have this truck. Mine is 4x2 without options though, can't speak for fully loaded 4x4s capacity. To really know, go have your truck weighed with a tank of fuel and passengers, then subtract that from the GVWR on your door, and what's left is good for the pin weight of the 5er, as long as you don't exceed you rear axle ratings, which you probably won't. I di mine, and I'm good for about 2700 pin weight, seeing mine is a stripped
4x2.

 

I have an 01 2500, and pull a 11.7K lb / 32 ft. fifth. Not a problem, but wouldn't go much bigger. Stay under your GCWR & GAWR. I also have the camper package, and so the overloads & sway bar came from the factory. As has been said before, keep good tires under the whole rig.