If you had the factory installed brake controller, Ford would have installed it in the rectangular hole in the top of the dash, just left of center above the A/C vent next to the radio. A lot of aftermarket controllers are small enough to fit the space, and the filler piece could probably fabricated into a faceplate or mount.
That's where I will try to get an installer to put the brake controller, when I add it to my 2013 E-350 van. Most shops, however, like to go for an easier place that minimizes work behind the dash.