The cheap HEI has a rather high failure rate.
The points eliminator kit generally works very well. don't need to throw everything out just to get a reliable ignition.
Now EFI is a completely different game. A stock distributor is fine for a retrofit kit (Holley Sniper) but if you go with a reclaimed stock EFI you want a completely different distributor (A TFI version that works with the OEM EFI). With the TFI you have to watch the gear material or it will eat the cam. Now you are getting into the complex world of trying to decide which way to go, how much to spend, how handy you are. No matter what you will be doing plumbing to get an electric pump in place and a return line run (there will be a return line even on returnless systems, it is just how the pump/filter works).