The anemone severely limits your choices of corals, since anemones can move around, they can sting sessile inverts (corals) to death quite easily. Most anemones can grow to a fair size also, they are probably not suited to such a small tank unfortunately. Many LPS corals also get fairly large, especially elegance and hammer corals. I'm sure they can be kept in a 12 DX, but not for very long if they grow. Also, with that many fish, your bio-load will be on the high side. Your percs MAY take up residence in an elegance or hammer coral, so you can experience the behavior they would exhibit in an anemone without actually keeping one. Hope this helps some.