You will get about as many opinions as there are brands and models of hitches. A little more info is needed in order to start to answer your questions, though. Year of truck and is it equipped with the Ford OEM puck system? Year of fifth wheel, design of front cap and placement of pin box (is it an older, squared-off front or one of the newer rounded and sculptured molded front caps)? Does the pin box stick out in front of the front cap or is it tucked back under.
The reason all of this is important is that not every fifth wheel requires a slider or a SideWinder for a 6.5' bed. We pulled a late-model fifth wheel (contoured front cap, forward pin box) with a fixed hitch on a short bed truck and had no problems at all. An older, square front end on the trailer would have taken out the back of the cab.
Rob