I had a dually a very long time ago when 454's were the ruling gas towing engines. It was not a bad drive and it towed my boat a lot better than my previous tow vehicle. More recently I had a 2003 Ford F250 4X4 Regular cab with a V10 and a four speed auto. It drove and pulled like a tank. Had the camper suspension and air bags and it towed my 12,000 pound fifth wheel trailer relatively well. It soundly proved all who said I needed a diesel wrong by a long shot. After three years of trouble free use I sold it for top dollar and got into a 2009 Ford F350 CC Dually 4X4, also with a V10 and auto trans (5 speed). It drives like a dream; like an entirely different truck. It also tows my trailer with a much smoother, true tracking and greater ease. Of course the engine is a 3 valve but the biggest difference for me is the suspension (no air bags), the tow/haul mode of the trans, and most of all the brakes on the truck and the built in brake controller. I enjoy driving it to work and to run errands even though I have a car in the garage. Keeping that big nalga in the lane is not even an issue. I would most certainly recommend a dually for what you say you need. Good luck with your decision.

 

Before I bought my dually I test drove several F350's with SRW, which I didn't like that much......just a personal thing, I found it a little "twitchy" in the rear.

Once I drove the dually, which I ended up buying, it was a no brainer for me.
I found the ride way more stable in the rear end, and towing is just a dream come true.