I know you expressed interests in a ribbon eel; which I do not have experience with..but I did own a snowflake eel for almost a year.
He was mean as hell. ANYTIME I put my hands in the tank he'd come and bite me, often times drawing small bits of blood. It became a two person job to scrape the inside of the tank, rearrange coral,etc. I'd have one person feeding him on opposite side of tank while I worked on the other.
When he'd eat he was really interesting, he'd do figure 8's in my hand. He did jump tank a few times, even with eggcrate. He returned without incident.
I got rid of him because he ate a clownfish I'd had for years in front of my 4/2 year old kids, lol. Other than that he was really neat. Very active fellow and definitely got attention of people passing by.
Mine was in a 47g tall tank with a whole lot of rock to run in and out of. I'd feed him shrimp mostly and would feed him pretty every 1-2 days. Very easy to keep I'd say.