I purchased mine from SuperBrightLEDS.com. I recommend calling in to verify you are getting the correct waterproof controller to work with the IP68 RGB lights. I made that mistake.... I ordered everything, wired it and go no lights...
Only certain controllers can work with specific lights...something in the wiring.
The controller is tucked underneath the trailer in the front.
You can order the RGB controller that is waterproof. Keep the remote in your truck and change your colors and settings as you cruise down the road....!
I just sold my F150 and jumped into a new F250 Diesel Platinum...so I'll be re-wiring everything again. So much fun..... like bcrider, I also wire everything to the truck. I used a 4 flat trailer wire harness to control the wiring. This way, when I turn on my underbody lights (On the F150, the steps lowered and raised when you opened the door) and this would initiate the lights on both the truck and trailer. I could also over-ride it with a switch panel I installed underneath the steering wheel (out of site) I'll post picks when done!
Let me know if you have any questions on the wiring. If real specific, you can give me a call...