Hey Harvey,
What about a longnose hawk fish! They are reef-safe, very peaceful, min tank size read is a 30 gal tank and the max size they get is 4" long if that.
The longnose is so cool to watch! Has quite the personality! It will always be watching you and when its not swimming it loves to perch on top of the highest rocks. Plus I think the colors of the hawkfish would look SUPER cool in your tank!
I was at Big Al's last night, there was (3 left) @ $50.00. Which is a great deal considering AI had these guys a couple of months back for $75.
Here's a link of a pic of one,
http://species.fishindex.com/photo_3..._hawkfish.html