I have an Anemone, Niger Trigger, Saddle Wrasse and a few others that have lived in the tank together for over a year now, and they have all been doing great. Trigger aggressiveness is really based on personality. sometimes you get lucky, and sometimes it will be a disaster. Out of all the Triggers, I personally think the Niger is the most docile to choose from.
Lighting will definitely be the key factor for success with the Anemone though. I use 2 250w MH
in addition to 4x65w pc
's, and the Anemone is still in the same spot when I put him in, which is a good thing. Good luck to you.