Mburnstein - You dont want the computer to have the I2S interface. This would introduce computer clock, power supply and ground noise into the signals. The best way is to use an external WiFi or USB to I2S converter with it's own power supply, preferably battery. My company makes these. The result in unlike any digital audio you have heard. Eliminating the S/PDIF interface makes a huge improvement by reducing jitter to infinitesimal levels. Here is a link to a recent professional review of an I2S-based system:
http://www.americanwired.com/audio/empirical/offramp.html
Steve N.
Empirical Audio