You should definitely look into the Sansa Fuze (not Fuze+) or Sansa Clip and Rockbox it (if the non-essentials are really non-essential). A lot of (self-proclaimed lol) audiophiles love Rockbox and the Sansas, especially the Clip, for the audio quality, ability to play different lossless formats (like FLAC), and customization of nearly everything in the player (equalizer, themes, games, gain, etc.). You can dual boot with Rockbox and the original firmware.
http://www.rockbox.org/wiki/GeneralFAQ