how long has your tank been set up for? i wouldnt reccommend putting ANY anemone even ONE in a tank that is less than a year old. also what kind of lighting do you have? anemones need a lot of light.
if you are truely interested in keeping clowns and their host anemones, i would really reccommend getting the book "clownfish" by joyce wilkerson. the book contains tons of info on both clowns and anemones, including compatibility issues and host anemone issues.
i do agree with the bubble tip anemone suggestion, the BTA will host both true and false percs and is relativly easy to take care of, as far as pacific anemones go.
in captivity clowns will often host soft corals instead of an anemone, so you really dont have to risk putting two anemones in the same tank.
i really reccommend you check out that book first tho, youll be so glad you did.