I don't have the Cub or Hensley, but please read...
Are you currently experiencing sway?
What is your current hitch setup?
I've towed with the same TV, and it was rock solid in every situation mother nature & traffic threw at us. I towed with that setup for half a season (~3000km). And to be honest, I just have an equalizing hitch, no sway bars.
All I can say is please do your research on "sway" and you will probably realize that it isn't an issue for a setup like yours or mine.
Oh yeah.. One other thing. you don't need a WD system at all with your setup. I had been hooking everything up for the first half of the season, and I noticed when I snapped the WD bars in place it didn't do anything (ie. there was no tension on the bars, didn't pull the front of the truck down). I adjusted it, readjusted it, spent a day working on it. So I did a simple test.
I measured from the truck fenders (both fr/rr) to the ground, then hooked up the trailer and measured the truck's fenders again, guess what .. It didn't change. My theory was correct, my trailer's tongue weight wasn't enough to make a dent in the truck's payload capacity. So for the rest of the year I didn't use the bars, and the best part of all, the truck's ride actually improved.
Although now that I have a different TV, i use the WD bars, but still haven't experienced any sway (7000kms).
Like I said before, read up on what causes sway and then you can make the decision yourself. Although IMO, even if you do feel you need some sort of WD/sway device, just get a dual cam WD/sway setup. Alot cheaper and does just as good of job (but the video probably isn't as convincing
).