i have a 135 and have 5 of them in there. They are all doing fin and the tank has been up for about three years now. Choc. chip stars, are not reef safe so if you are planning on keeping corals, i would pass these guys up. They also have a tendency to bulldoze your rock, meaning that they can move it and cause whole sections to collapse. I had one customer that this happened to and when the rock fell, it broke his tank and was a total friggin mess!
If you wann keep a reef try a linkia star or a fromia star, but only after your tank has been established for like a year!
good luck
jon