Is there a Music Player for this?

I'm looking for a quality music player without a built-in DAC or hard drive for the music files. So, a hard drive for just the operating system is fine. I want to store my music files on an external hard drive using either an eSATA or Firewire connection to the music server. And, I want to use either a coaxial, optical, BNC, or AES connection between my DAC and music server. I also need to use my iPad as the controller.