After scouting the resourceful Computer Audiophile forum for a while, I decided to get myself a new Mac Mini 2010 model, complete with 8GB Ram and will be configuring it purely for audio use. To be controlled headlessly from another Mac using screen sharing and will be using my iPad to control music streaming from iTunes (with PureMusic or Amarra) wirelessly through a secure wifi connection.
I will further enhance the unit by installing a Solid State Drive in it to make it completely silence of noise and radio frequency inferences. Music will be store in an Oyen digital separate firewire-connected drive. Users report that this Mac Mini as transport, coupled with state of the art USB DACs are sublime. Will see when I finish upgrading the hardware, configure the OS, and get my hands on the Tranquility SE USB DAC.
Now, if I am less of a Mac/Apple fan, I would consider as well a specialized headless UNIX machine design to just playing music. So in addition to whatever the Mac Mini can do, the Auraliti MPD machine can output high quality analog audio, plus a proper coaxial SPDIF digital output.
No moving parts and super green (like my mod Mac Mini) and design to do nothing but output music. Driver-free USB for most USB DACs as well. At $799 - I may try it out if I have another house or something.