Hiya Keng
Natural hosts are H. Magnifica, S. Gigantea, and possibly Malu. If you want to guarantee they go in the anemone get a mag or a gigantea (good luck finding a good looking one around us though). In general A. Ocellaris will eventually associate with BTA's but it is not a natural host in the wild. (I do have some that are with BTA's, and some others that refused to associate with them for over a year).
The easiest nems to keep are definately BTA's, if you go with either a gigantea or a magnifica, they get very large and may wander. I would not advise getting an S. haddoni as they like to eat fish (sometimes including the clownfish). Best of luck and if you have any more questions you can ask me anytime.