One part is settled as far as the ribbon eel is concern, it not be a suitable eel for your SF as a tank mate. Now if this tank is the 150, i not know the other tank mates with the SF, but either eel you go with, will do fine. Now know this, The name you gave with its common name they not go together. I know, you do see it that the Ghost Eel is with the name (Uropterygius concolor) which is really a snake eel
You see, the name that goes with (Uropterygius concolor) is Unicolor snake moray and the name that goes with the Ghost Moray is (Gymnothorax phasmatodes) 8O You will know that at sites or fish stores that these names do get mix in with other species.
Happy New Years Folks