The wiring is usually all there...
The 2007 bodybuilder guide has good info on trailer wiring starting about page 273...
Best to pull the blank panel / cubby and double-check brake controller connector connector is in dash and check behind bumper to make sure all trailer circuits / connector is there. Some times fuses and/or relays need to be installed In underhood trailer tow relay box. GEM / module body controller may need programming update to recognize trailer brake controller. A good ford commercial / fleet truck dealer should be able to run your VIN and get you pretty accurate information for your specific VIN ( as usual a lot of it depends on the person looking up the information : - )
If you want to send me your VIN I can probably have it run, not likely to be too quick though : - )