Choices choices choices................
When I ordered my truck there was only one option for hitches if using the factory under bed mount, the Ford offered Reese. But there was promises of soon to be options.
By the time my truck came in Hensley had their adapter plate ready.
That plate is pricey and very well made.
The advantage with this plate if you have the factory under bed kit is that any Reese style rail mount hitch will work.
The B&W world is certainly full of devout followers with the turn over ball system - kit. Personally, after doing my own research, I never cared for the the B&W as it uses the trucks bed for support. For me, I want all my towing stresses on the frame. Granted, most of the towing is done by the single center point, but the hitch still relies on the bed.
B&W has listened to the consumer though, and they now offer a model that drops into the factory under bed mount.
I had a PullRite SuperGlide in my previous truck, and for sliders I don't think there is anything on the market that can top the auto slide feature.
I am using a Hensley TS3 now, also a well made robust (heavy) hitch.
Since the original poster will be trailering a toy hauler, and a large one at that, I would suggest looking into air ride hitches.
An air ride hitch allows me to keep my trailer where I want it depending on the load. My toy hauler weight varies quite a bit from being almost empty with no water or toys for a 3 day trip to the county park to being well maxed out with 110 gallons of water, motorcycle, golf cart trailer's gas tank full and provisions for a couple of weeks.
And you should consider air bags. You didn't say if your 350 was DRW or single. With the DRW, you will be below level in the rear with that trailer hooked up.