I would avoid blue/black ribbon eels, often it's survival has little to to with experience, I've seen many that may have been injured or show signs of cyanide which seems to eliminate all chance of sirvival. If one was eating frozen well it may have a decent chance but this is very rare.

You can get a ghost ribbon eel which actually has a good survival rate and is typically a hearty specimen. I've kept these before with nothing but success although they do sometimes still require a bit of work to ween onto frozen.

Our LFS hasn't been able to keep them alive for very long or sell them so they stated a year or two ago that they will no longer bring them in. However with all of the staff turnover in there that could change... A snowflake moray on the other hand is pretty easy to take care of if its basic needs are met. I think I've had mine for 6 years now.