Radio Shack sells universal wall warts with "adapt-a-plug" fittings to connect to just about any device. It's a bit of a hack but you'll be up and running quickly; just make sure you get the polarity correct.
If you want something without adapters, visit Electronic Parts Outlet on Fondren; They almost certainly have one that will work.
For mail/web order, Digi-Key, Mouser Electronics, Jameco, JDR Microdevices, and Parts Express all have a wide variety of power supplies. You might even find a steal on one in surplus inventory at places like Halted Specialties or Marlin P. Jones [mpja.com] ...
You will need the same voltage, >= current rating, with the same plug diameter & length & polarity.