A recommendation (Score 1)

Don't. If you're looking for people that you're going to be calling superstars. You're going to get just that, ego and all. Although they may be the best programmers on the face of the earth, generally they won't live up to the reputation they've built for themselves. They won't do it any other way than their way, for better or worse. While I'm not trying to advice you against hiring competent experienced programmers, in my experience "superstar" tends to bring out the worst. Best of luck.