I removed the original brake and drums, cleaned up the axle and replaced them with hub and drums from etrailer.com The axle is a pretty standard 3500lb axle and the new stuff fit really nice. I have also got the Redarc Tow-Pro Elite brake controller, really good piece of kit and small when fitted. That way when traversing down a mountain, i'm not being pushed by the trailer.
*edit* I forgot to mention, I got the electric brakes hence the need for the brake controller.