OK. Am I the only one reading this that wonders why someone would buy a 3/4-ton truck with a 5.4L engine? Some day, a larger, heavier trailer may be desired and then that engine would be insufficient.
In late 2006 I bought my 2500HD with the 6.0L Vortec engine - 4:10 rear end and 4-speed auto transmission with TC lockup clutch. It towed my Outback TT admirably (6700# max weight). But I certainly wish I had the Duramax/Allison setup now, with my 32RLDS, which has a dry weight equal to the max weight of the Outback. I weigh in at a tad over 9000# and get a miserable 7.5 mpg on flat ground - and wishing I had more power.
IF you can afford it - when you buy the F250, try to get the diesel engine. It will be more expensive, but you will not regret it - especially when you get that 3-foot-itis in a few years and want a new TT.
Just my opinion.
2015 Jay Flight 32RLDS Elite
2012 Chevy 2500HD Crew Cab LTZ (6.6L Duramax/Allison)
Equalizer Hitch (1200# bars)