I did a lot of home work before buying my 5.0L F150. I wouldn't buy either of your choices.
The Ram Ecodiesel is really just a grocery getter with no payload to do any real work. The payload is less than 1000 lbs so you really can't have a heavier tongue weight and people in the truck at the same time without going over GVWR.
The Ecoboost was offered in 2011 - 2014. All models of the Ecoboost have had some serious problems but earlier models were worst. From the complaints I keep reading, Ford never corrected the condensation problem that happens in the intercooler and causes the truck to stall and go into limp mode on expressway and highway, full throttle situations.
They CAN also have carbon build up issues from the direct injection (as other direct injection engines do) but it's worse when carbon breaks off as it could damage the turbos.
Also early models had spark plug gap problems. Do some google searches to see for yourself. BTW, Ecoboost Crew Cab 4WD has a lower payload than the 5.0L Crew Cab 4WD for some reason. Ecoboost only has a 7200 lbs GVWR while the 5.0L has a 7350 lbs GVWR.
If you must get an Ecoboost, I wouldn't get any earlier than 2014. As far as getting any 1500 Ram, none have any payload. The Ram 1500 Crew Cab 4WD trucks have a very very low 6800 lbs GVWR. You'll be running out of payload with a heavier tongue weight (any TT) with people in the truck.
I would recommend a 5.0L or 6.2L F150 with careful payload considerations or a 5.0L with the Heavy Duty payload suspension package. Better yet either a a Ram 2500 or a Ford F250.
I really love how my 5.0L tows my trailer. A lot of lower rpm torque and upper end power as well. Just get the 3.73 axle with the 5.0L.
Here's a review how great the 5.0L tows.