Best 5W Hitch for short bed pickup - 5.5' or 6.5' bed

For the cost of a 5th wheel receiver and a truck with the capability to do it, just pay for that service if it truly is that infrequent. I've never seen a truck with 55' ed that has 2500+ pounds of payload to handle that. That's into 3/4 ton truck territory and it does not sound like you need that capability for other reasons.