OK, F it, get the Dmax.
Its not for the power, gassers have almost as much and will be faster unloaded.
One word - Control. Stepping to the 2500 platform delivers a heavier duty frame you will appreciate. 1500 can Tow loads fine but Control and Stop; not as well. Towing a travel, horse or car trailer are different because they will usually have electric brakes that react when the brake pedal is pushed and can be manually overridden for even greater or less force.
Our boat trailers are Surge braked so the trailer has to already have momentum pushing on the truck to begin braking.
The tipping factor of Control with the Dmax is the 1,2 "punch" of the Allison trans brake combined with the Turbo brake. It is nothing short of amazing how much slowing/stopping power is available before you ever touch the brakes.
Lets be honest, you know you are on the edge of towing your load with a 1500.
My trailer, boat and fuel scale at 6800#. Load up people, wakeboard gear and weekend gear; a 1500 is technically over its load limits. I know, I have done it on a swap of costs with a buddy's F150 and my boat for a weekend at the lake. My daily driver is a 3500 single axle, CC, LB Dmax and there is NO comparison, especially on a twisting hill decent or hit a highway corner a little too fast.
I'm not an advocate spending money just because one has the financial ability. IMO the Denali package is a bigger waste than the Diesel option, but each to his own. The Denali 2500 has softer suspension and spring pack than a standard 2500 so there should be plenty of cushion to the ride yet a more capable tow platform.
The one add-on I would advocate is a water/air/fuel separator/lift pump like Air Dog or FASS. You will likely never change a filter in 3 years and the 1.5% additional cost ($800) is the best insurance you could buy for staving off a host of trip or engine ruining problems. This is not a performance add-on and will have zero effect against warranty.
As for the Diesel smell on one's hands.......I have never heard something so whiny. Most consumer pumps are very clean and have a slower pump speed to avoid the burp. High speed diesel lanes can be dirty but rarely is that one's only option. Keep in mind with an average driving range of over 600 miles, you will likely touch a pump less than 20 times a year total.
A canister of wet wipes under the seat is a good idea regardless of what you drive.
1991 MariStar 240sc, 454, tower, WetSounds, Krypt and Rockford Fosgate