I dont think eels are as fussy eaters as Chestnut portrays. Ok, they do recquire more work, and a little time and effort, but in the end, if you provide decent food, and acclimate the eel properly, you can keep them rather easily. Getting to eat is the hardest, once they have, there is no turning back!
The biggest problem is tank size. A small eel will quite happily stay in a 55 for a few years, but the tank will probably need up-grading in the future.
As for them being docile, well, yes, they do hide and are nocturnal, but should get along fine with angels. Depending on what sort of cichlids you plan to keep?
Keyhole cichlids would be fine with an eel. It depends. An 'O' would probably consume an eel given the Oscar had the right temperament.
What will u stock it with?