Though the situation seems well in hand, I'll through this in, for what it's worth. My best friend and playing partner back in school favored an open C tuning--he used flat-wound strings with a 60 gauge string on the bottom. He favored really cheap, no-name guitars, which actually sounded great this way. I suspect that you could find say, a Hohner or Seagull, or some such instrument that would do surprisingly well--