Does it have to be reef safe? lame....
I guess with that restriction, I would have to agree with Alexander and go with the flame angel. I have had several of them over the years and none have touched coral, but will nip at clams. But, I am not a huge clam fan so it works for me. I had a coral beauty in my current set up...:death:... but thanks to flatworms, he is no longer with us. He would have been a close second to the flame angel.
If you are planning on going bigger, I agree to stop spending money on this system and upgrade ASAP. When you do, I always recommend going as big as your home and budget will allow. A 90 is a good sized, medium tank that gives you lots of options, but if you can get into a 125 or larger, things really start working in your favor with bigger fish that just make your heart melt. :Cheers:
-Doc