I have a F150, Ecoboost, super cab, long bed, 4x4, with the max tow and payload package. It pulls a 4500 lb Airstream like it wasn't there. I chose this set up so that when I am not towing I would have the high mileage of an untethered Ecoboost which comes in at about 20 mpg on flat ground at 65 mph.
We travel and tow perhaps 40% of the trucks use. That makes the 150 a good economic choice for the other 60% of non towing use. However, the Ecoboost drops to 13-14 mpg when towing and, it is lower in the mountains. If my percent of towing time exceeded my non towing time, I would probably go with a 250. But, since so much of my driving is non towing, I am willing to accept the weight limits of a 150.
So, if you can keep your towing need a bit under the F150, Ecoboost max and, you will bbe driving a good percent of the time non towing, go for the 150. I highly recommend it. If you think that you will need to get heavier some day, or will be towing most of the time, I suggest getting the 250 now.