Have had both and there is NO comparison, go with the Dually. If you can, keep your 99 and then you will have a choice for awhile, just in case you don't like the dually. The market for 99-03 7.3 PSD is very good and you will get top dollar for yours, plus it will sell quickly, when you're ready.
Bob & Betsy(FishNFanatic) - USN Aviation Ret'd '78 & LEO Ret'd '03 & "Oath Keeper Forever" '05 HR Endeavor 40PRQ, 400 Cummins-Pulling our '11 Silverado LT, Ex Cab 6.2L NHT 4x4, w/2010 Rzr or 01 V Star in back. Where the wheels are stopped today
I would do it. We own a shortbed 01 7.3 Single wheel and the stability of using the dually would be the deal sealer. My question though is this going to be a daily driver also. How often will you pull your trailer? These questions I would ask myself first before making the deal. Just my two cents worth.
All I can say is that we went from a 2500hd to a 3500hd dual wheel and would never go back to towing our 35'6" 5th wheel with a single rear wheel truck. To me it was like night and day the 3500 dual wheel is so much better and even better if you dont use it for a everyday driver.Good luck