A bulb buddy of mine said he saw a 2x250 sylvania ballast on the bay, but he couldn't find it after that. I also saw an interesting ballast. It was a 480v CWI ballast, with the output coil being tweaked and twonged to run two 400w MV lamps in series on 480v. It was a good ol boy, made by universal. I'll see if I can find it.