I had the F250 shortbed crew cab. Upgraded to the F350 longbed crew in 2012. The two vehicles drive almost identical. You will enjoy the longer wheelbase pulling that big trailer.
I have the 39 gallon tank and added a 60 gallon in-bed reserve. I wouldn't do it any other way.
Also worth noting I live in Houston and it is my daily driver. I'm in and out of parking garages, parking lots, heavy traffic. Granted, I'm fairly proficient behind the wheel, but still there is not that much difference in the two bed sizes.
Test drive them both and see for yourself.