What are you towing with??
If you have something full size you won't need brakes!
I have a full size chevy pickup and I will tell you there4 is no need for trailer brakes.
I hate brakes and bought a brand new trailer and had them left out.
But if you must, try here for your parts, Labore in another story if your noit going to do it yourself.
http://www.championtrailers.com/
Only the front two wheels have brakes.