I can give you some additional advise no one so far has. Stay away from the low end lightweight trailers, they tow like complete crap apples to apples. I've seen first hand how 25'-32' lightweights from Forest River, Keystone etc tow compared to nicer ones with heavier axles, better suspensions and stiffer frames like Highand, northwood etc and it's night and day different. A lot of these lightweight trailers also come with suspect 14" and 15" tires, combined with axles that are working at their max capacity and tires with soft sidewalls it makes for a scary ride. Cheap trailers tend to be cheap all around so when frames flex and twist it translates into the towing experience as well. Also tank placement, weight balance side to side all play a roll in how a unit tows. Also make sure the trailer is aligned, believe it or not most trailer alignments out of wack and when the tires are pointing 4 different directions it's not fun.
The Open Range builds some nice units, they are heavy but I think you will be fine with the expedition especially with some good LR E tires and the correct hitch set up (get the stiffest equalizer bars you can to help smooth the ride and distribute weight). The biggest issue for you towing heavy is going to be the ecoboost, while they make great power it's for limited times (out of 40 plus ecoboost we have yet to have one go over 110K miles without an engine failure). Otherwise give the Open Range a try, it will be more enjoyable than a similar light weight unit simply due to the quality construction and components used.