I am going to make a 47gal reef aquarium as my next project. The only livestock I want in particular is an eel: either snowflake or chainlink.

Anyone have some ideas for possible livestock options?

both eels you listed are crustacean eaters. my 12" snowflake will even suck hermit crabs out of their shells. until your eel gets really big like 3' you should be fine with most fish as long as you keep him well fed. my ocellated moray leaves his tank mates alone except for small lion fish which he finds tasty for some reason or another. just remember they grow pretty fast and you dont see them much and they will eat any crab or crunchy invert in the tank,.

Thanks!