I have a cheapie Drawtite controller, set on the sloped area in front of the handbrake, with the manual slide at the top. I don't love it, would prefer something that adjusts itself for stopping rate. Most controllers are timer based, you can adjust how hard it brakes and how quickly it reaches that maximum. I tow a tandem 16' trailer, about 3500 pounds, 1000 miles a month. My main reason for having trailer brakes is for when I have to panic stop, so I like keeping the brakes set to max. The problem is, I plan ahead and stop gradually most of the time, and don't want the trailer brakes to come on and yank me to a stop. At least the controller is at hand if I need to add braking in a hurry.
Wire it yourself! I hooked a marine 50A breaker to the battery, ran 8ga wire through a grommet to the driver's kick panel, terminating with a ring. A 30A fuse and 12ga wire would've been adequate and easier to do. From there through a fuse holder with a thermal resetting 20A breaker, to the controller. Tap into the wire above the brake pedal sensor with a simple squeeze type splice. Run ground from wherever, I used the one under the center console. From the controller run the brake control wire to the back of the truck, along with a power wire (keeps the trailer battery charged). I relayed the power wire so it's only on with the accessory power, you could just tap off the cig lighter wire to. I didn't want my battery always hooked to the trailer battery, but I don't think it would hurt anything. Just put a fuse on it. The wires all fit in a deep channel under the plastic trim at the bottoms of the door frames. Get a 7-pin adapter for your existing 4-pin plug, attach the power and brake wires to that. I did all this in one day for under $100 including the controller. I also ran extra wires for other stuff, and plan on wiring my wife's 80 so the experience will be handy.
Did you get the Airlifts? What an improvement they are. I don't really notice the trailer other than stopping distances.