Any boss type power supply will work. Make sure it has 9v / 500mA or so power and you should be good to go. Its ok to overdue the mA, but not the voltage. Usually its good to have some ampage on reserve for adding more pedals, ect.
"But lay up for yourselves treasures in heaven, where neither moth nor rust doth corrupt, and where thieves do not break through nor steal:" Matthew 6:20