I've towed the same 38ft 5th wheel with 4 different trucks over the past 20 years.
First was a single cab, single rear wheel (SRW) 4X4 Longbed
2nd a 1 ton dually crewcab long bed
3rd a single cab, SRW, long bed
Now a MDT crew cab long bed.
By far the best is the current truck it has a 53 degree wheel cut so it will turn circles inside of any of the other 3 trucks.
My next favorite was the 1 ton dually crewcab....the ride and stability far outweighed the few times I had to get the 5th wheel into a tight spot. I even parallel parked the 5th wheel several times in our favorite campground where the spaces are 45 feet long and the RV's park nose to tail, basically bumper to bumper.
Unless you have a spot where you constantly need the manueverability, I think you'll find the crewcab longbed provides more room for stuff and passengers. The extra weight helps with stability and ride quality.