what do i need to convert to power brakes

A good set of Manual Brakes can stop pretty well. Alot of the conversion to disc was about weight reduction. I know people will argue with me but I love Drum Brakes. I guess it's the Tractor Trailer driver in me. They say a Big rig won't panic stop too well but I've had to do it many times. Manual brakes just require the driver to push harder with their foot. Of course...always follow back at a safe distance.