i dont have one but i did lot of research about them when i was thinking of buying one.
I read they need to be kept in a small tank w/o any other fish. There are some small ones that get around 3-4" max. IMO best looking one is wartskin but you can find anglers in every color. Red, black, striped, yellow...
Why you need to keep them in a small tank and w/o fish is because they have a huge mouth and a 3" angler can eat a 3" fish, shrimp, crab...
in a big tank they might not take enough food and with big fish again it may not take enough food also tangs, butterflies, angels, foxfaces, etc may nip anglers because of the algea growing on them or the "algea looking" skin of angler.
You can feed them same w/ a lion
Good Luck