What are your plans for the anemone? By that I mean are you hoping that it will host clownfish? If so, I agree that a BTA is your best bet. I also agree that it's a good idea to wait awhile until your tank has stabilized and you've got your arms around good maintenance practices (I think the six-month rule is as much about the aquarist as the aquarium).
On the other hand, if you're just looking for something colorful and easy to keep and you're not trying to find a host for clowns, you could try maxi-mini (s. tapetum) anemones or maybe a rock flower anemone (Epicystis crucifer). Both of these anemones come in very pretty varieties and are easier than even BTAs, but they will not host clowns.
Hope this helps.