I've never owned a 4WD truck and I've owned several trucks in my life. Currently on my 5th one. Through the years I've always ordered 2WD with limited slip differential and only been stuck three times since 1978. It always happens in my back yard when trying to put the boat under the storage shed. I cannot justify the added expense, height and insurance cost of 4WD. Why go down the road hundreds of thousands of miles in the past 40 years with an additional differential and transfer case I'm not using.
I will also comment on your engine selection. The 7.3 V8 gas engine from Ford with a 10 speed automatic is getting great reviews on YouTube and other forums. The additional cost of a diesel is not necessarily a must have unless you are pulling HEAVY all the time. If your trailer weighs less than 12,000 pounds it's not necessary. When I replace my Ram Cummins this is what I would choose. In my opinion they have ruined the diesel with all the emissions hardware. I don't need to spend an additional $8k for a diesel.