Upgrade to Disc, or do Alterktion???

It all depends on how much you want to spend. I'm too cheap to spend any of those amounts you mentioned, so I found a 73 and later A-body single piston disc brake BBP front end out of a junk yard for $50 bucks and installed everything myself; of course I bought it about 10 years ago. If you choose this route, make sure you get the upper control arms, spindles, discs, rotors, brake lines, proportioning valve, brake pedal push rod, and the dual master cylinder. If the master cylinder turns out to be bad, at least you have a core for turning into the auto parts store.

Don't get me wrong, I think the RMS stuff is awesome, but I can't afford to come off that kind of money.