I have an SX with PP, I didn't put it in but it pulls well with factory ballast and a couple of people. I'll look at the NN and KDW, but you could start with an NN of 70 and a KDW of 170 or so. I'd give it a test with the stock settings, if it is sluggish and overshoots, make the KDW larger and/or NN smaller. If it is twitchy and moving the throttle excessively, do the opposite with each value.
As for the brake system, they are actuated by a fifth pin on the Wesbar connector, it is connected to the reverse lights on the vehicle, and activates a solenoid that deactivates the brakes. You can also do it manually by inserting a small piece in the port side of the brake actuator, it prevents the sliding actuator from moving and depressing the master cylinder piston.
There's also a way to do it with a four pin connection on your vehicle, you plug the fifth pin on the trailer into an active one (vehicle lights) on the 4 pin vehicle plug.
