I run Tekonsha Prodigy. I have a p2 and a p3. price is average, and their small. Controllers fall into two categories. Ones with a G-Force sensor and ones without.
The G-Force sensor adds braking the harder you stop and can be mounted in almost any position. The other does something similar but not as good. You also have to mount them more flat.
Its basically two diffrent generations and the old ones are still being sold.
There's a real expensive remote unit made by Redarc that people like. It works well and all you have in your dash is a knob.
The ones I run have a few presets. I need diffrent amounts of braking based on pavement or dirt. If you tow street and dirt, its nice to not have to play with the braking. I just push a button and go.