brake drums

Not too long ago I snapped a brake line trying to replace my wheel cylinder on my drum brakes and we decided to replace basically everything past the portioning valve. I replaced the steel lines front to back, and replaced the brakes themsevles with the full brake system kit from black magic, so...

So sparing the details of how it happened I did some damage to the rear left brake hub. This is causing the wheel to sorry if oscillate as it rolls, pretty dramatically at that. Need to fix this. What exactly is the part called that needs to be replaced and where can I find out how to do it?

I need to replace the brakes on my TJ, and I am thinking about upgrading the rear brakes to disc/calipers. Any pitfalls in doing this? Suggestions on any particular kit/parts I should go with? While I've got the brakes removed, any advice for other maintenance I should do? Our jeep is mostly...