Unless you plan on upgrading to at least a 75 gal tank I would not put any oscars in it. I have a single Oscar that has out grown my 55gal. Same is probably true with a lot of the other cichlids. If you want cichlids I would suggest searching for smaller ones, such as some rams, or maybe shell dewellers.
Also if you end up putting Oscars in it anyways, your zebra danios & 2 mollies will end up as food for them most likely. There is a fish profile tab at the top that you can look at different fish, so you can get nice fish that will go well with you current fish.