Peacock eels are pretty sweet in your tank. they do hide under sand or whatever your substrate is and can be hard to find at times. A personal opinion for a fish would be a Blue Ram Cichlid, they have amazing colors and dont get too big.
Well I heard Blue rams are kinda difficult to care for and I'm still kinda new.
And I have gravel D: Will it be bad for the eel.
So I'm thinking of getting a peacock eel and a firemouth