Sorry to hear about all your bad luck.

I ordered a kit online in I think 2004 and swamped out my drums for stainless steel disks on a tandem axle trailer in less than a day. I also bought/installed the reversing selenoid which I recommend. The selenoid went at some point and I could still back up with the surge brakes but not on an incline. Driving was waaaaaay easier with stainless steel disc brakes.

The only regret I had was that when I was tightening one of the bolts the wrench slipped and my thumb slammed down on the edge of the disc. Cut to the bone like butter. A tetanous shot, numbing injection, scrub with a stiff bristle brush and 7 stitches later and I was back finishing the job.