If your heart and mind is set on a gasser, go for it. But as the majority of folks have said, you'll be happier & better off with a diesel---myself incl w/ that assertion.
Let me have you look at it another way. We bought a '15 F350 CC, 6.7 PSD, 4x4, srw, sb in Dec '14 thinking this will be truck enough for now/future.. At that time we had a Cedar Creek Silverback that weighed 10, 800 dry, 12,800 fully loaded w/ 1k to spare. Combo was great together. Last year we upgraded to new 5er (in sig). While over on truck, I wasn't worried about it. HOWEVER, never really gave the tires much thought., But based on weights from CAT scale, towing it didn't bother me here locally. Locally as in within state or within 500 miles from home and 70-80 degree temps. Enter our summer vaykay trip this year. Dead of summer and off to FL. NOW the tire question comes into play----heat not only from rotation, but ambient temp AND from blacktop temps. Again, not concerned about the truck, but others may differ-- that's ok. I just had this nagging gut feeling inside about the tire equation. Long story short, today we are picking up a '17 F350, cc,4x4, 6.7 PSD dually. Didn't/don't want to, didn't want a truck w/ "training wheels" (as my son calls them), but now I don't have to worry about tires being a problem.
I knew when we bought the new coach we'd be over as I knew there is a "fudge" factor built into trucks and just never took tires into account.
My point is that while a gasser may get you by / job done, if you're going to be doing a fair amount to towing, long distance, hills/mtns or in my case-- going from warm to VER WARM climate and tires are weak link, you will be much better off in the long run w/ a diesel from any of the 3.