You'll want a dually for that trailer. If looking at modern diesel pick-ups I'd expect to get well over 200,000 miles out of a truck so you may need to change your definition of high miles. My own '05 Chevy Duramax dually has over 170,000 miles on it with virtually no problems and still going strong. I'll be rather upset if I don't get 300,000 miles out of it.
Ford diesels have been the poorest choice from about 2003 thru 2010. The 6.0 and 6.4 engines were quite problematic and the 6.4 got very poor fuel mileage. I drive an '03 6.0 for work and it is a complete pile. Comparing it to my Chevy there is no contest.
You will hear lots of people tell you the "they all have their problems." These are normally Ford owners. The GM diesel and trans. have been pretty much problem free since '06. The Dodge Cummins has been a very good engine for many many years. Their early auto transmissions were pretty poor but that got straightened out around 2005 or so with the 68RFE transmission.
If you want a Ford for some reason the 2011 and up 6.7 diesel seems to finally be a winner for them.