My only advice is you can't have to much truck when towing! I tow with a 2017 F-450.
We spent the summer of 2016 in Alaska with our old 30' fifth wheel. We were set up in a Camp Ground in BC off of the Casier Hwy. when a new arrival started down the gravel road desent to the pull through site next to ours. They made it about 50' before the trailer began to drive his undersized truck. Pushing it down the hill with his brakes locked up. He finally slid and turned off the road onto the grass and got the rig stopped before he slid past his site. Not enough truck for the toy hauler he was towing in that instance. Just because you can pull it doesn't mean you can stop it. Gravity is evil at times. I also suspect his brakes on the trailer were sick or the after market trailer brake controller he was using was not set correctly to activate the brakes enough to help the truck slow and stop the trailer. It was either a 1/2 or 3/4 ton SRW he was towing with.
Good luck with your decision.