Sway control needed when pulling TT with DRW?

You could just ballast the back end of the trailer to take some tongue weight off and use your Hensley. You might have to add a receiver hitch to the rear and mount a rack to it, but that is going to be a lot easier than buying a new dually. DRW trucks have their own set of "problems" (ride, parking in tight quarters, two more tires to buy) and it will still be "bouncy" without a good weight distribution hitch.