Get the hitch that's made for your installed prep kit, the Reese Elite 5er itch. That's a premium hitch with a premium price, but you'll be glad you bought it.
Since you have an 8' bed, no need for a slider hitch. And since your trailer grosses less than 18,000 pounds, no need for a heavier duty hitch that the Elite 18k. (But if you prefer to have a lot of cushion between enough and way too much, the Elite also comes in a 25k version.
Here's an 18k from etrailer.com:
Reese Fifth Wheel for Ford F-450 Super Duty 2011 - RP30142
Yep, not cheap. But you're worth it.