How much do you need to carry in the bed? And how tall is it?
If you order an F350 and are worried about being over on the sticker because your camper is 90% of what your expected haul capacity is........that might still be the wrong truck for you. I have no problem with an F250 getting maxxed out, because it's just a derated F350, and it can handle it with a few mods. But maxxing out a F350 is not a place you want to be.
My F250 XL, (loaded XL), CCSB, gas weighs 6900#. Expect the 350 to be 7000# because of the heavier rear axle. Any diesel I saw on the lot was a full 1000# heavier. Beware the Lariats, KR's, and Plat's, they are at least a 500# penalty.
My F250 has a 3100# capacity and a 10,000# GVWR. My 2015 F350 chassis cab has only a 9800# GVWR. The numbers don't always make sense. The computer that prints out your door sticker, knows the weakest spot of your truck. Might just be a wheel or a wheel bearing. No idea why my Reading box on my F350 makes it's rating so low. You'd think the box is just cargo, and the trucks rating would be the same as a regular cab with a bed, well over 11,000#. But it isn't. Maybe my company accidentally ordered floppy springs?
My F250's tow rating is limited by power to 12,500#. 4.30 gears bump it up another 1000#, IIRC. The F350 DWR 4.10 diesel can tow over 15,000#.
If I'm splitting hairs with the sticker to get my slide-in camper legal, than I'm buying a truck off of the lot that has a sticker I like, or I'm going big with a DRW or F450.