Trailer Brakes

You are looking at about 200 to 300 dollars for the electric controller.

Electric brakes aren't the best for off road work as the magnets and linkages inside wear badly on rough roads. But most seem to use them these days.

I had an O'Briens for a few years and found the electrics were OK and like you I didn't do heaps of off road.

A tekonsha Prodigy ( a good one) is under $200 and only takes 4 wires to install.
This is probably the best model and all you have to do is follow the instructions and make sure you have heavy wiring running back to the connector at the rear. I actually use a piece of dual 6mm connected together but is probably a bit of overkill. One 6mm should be enough.
Depending on the vehicle you can connect the signal from the brakes to the cold side of the brake light switch above the pedal.

Prodigy, just done 16,000klms last trip with camper trailer with boat and boat trailer etc on top, great set up with the controller and not a spot of bother. Very happy with the choice

Trev

i have used both braking systems - on boat and caravan -- both have there own advatnages - but will tell you this

with electric brakes - you can manually adjust them from inside your car - this is very handy especially when you overall weight can change dramatically from one trip to the next , something you can not do with the hydraulic style braking systems

Boc

Having had two boat trailers and a caravan with over ride brakes and now a CT with electric brakes, I would have electric brakes EVERY time. Yes, override brakes are self adjusting. Yes they can be simpler particularly if discs BUT the trailer must push against the tow vehicle for the brakes to activate. This means that you have inertia from whatever weight your trailer is, that is trying to push your vehicle along the road for the brakes to activate.
As has been said, electric brakes are controlled from within the car. The prodigy is a great piece of kit and available fairly cheaply though an advertiser on this site (no, not me!). It allows you to adjust what braking force and the starting strength (through 3 settings) and it has a manual override lever. The other thing is that, if needs be (say for loose downhill treks), you can increase the trailer braking force and use it like an anchor to stabilise the whole rig. Works a treat also in wet weather when you definitiely don't want a trailer pushing you down the road.
My opinion anyway.
The advantage of over ride brakes (and why they are popular with rentals) is that no car rigging is required. Hook up the trailer and you have brakes. They too, however, also need correct maintenance and adjustment.
Cheers
Rob