I would go for the powerstroke.. not just because I own one either
I had a gas F150 befor I bought my diesel in April this year.. I do however have alot of years driving ford diesels... since 1994 I have had these wereckers
1985 F350 6.9L non turbo
1989 F450 7.3L non turbo
1997 F450 7.3L turbo
1999 F550 7.3L turbo
2003 F550 6.0L turbo
all these trucks have performed very well with no big issues (except the 6.0L in the 2003 but it was all covered by fords)
I however know a few people who bought Dodges for towing horse trailers car haulers campers etc... I will say the Cummins is a great motor, its the rest of the truck that has issues.. they have alot of front end part and tranny issues with the autos (way worse then fords)
Over all I love the interior comfort and body style of the superduty over the dodge too!! So I'd buy the Ford myself for these reasons
If I had the $$$ Id buy a superduty and swap in a cummins you would have the best looking and comfortable truck with the reliability of the cummins( not that the 7.3 isnt reliable)