Most High end fivers come with shocks on them which really they all should for safety. Shocks will make a real big difference. Rolling across country we hit some really bad roads but I could see the fiver in the mirror bouncing a bit but we never fel...
Another great tire for trailer ST is Tow Master never any worries coast to coast. Discount or American tire. They also warranty for road hazard and dry rot.I also just purchased Carlile for my car trailer. So far to few miles to mention.
The installer of the hitch will make the adjustments needed to tow level. Besides when you back under the trailer with the hitch installed, the pin weight is going to drop the truck bed and rails down from the weight of the pin.
When we talk about great hitchs, we have been using a draw tite fifth wheel hitch a product pretty popular with U Haul. Trouble free comes out easy. You can break it down or pull it out whole.