Epicystis crucifer (flower anemone) is a good choice, though they are not a host to clownfish. Also, condylactis gigantea is hardy, not a host anemone either. The flower anemone is very hardy and remains stationary. There are pretty red and green ones sometimes available. Drs. Foster and Smith sometimes carries them as I'm sure do other online vendors. None of the host anemones are considered beginner or especially hardy.