CaM
You'll need a XLR breakout cable, can your processor not accept the spdif out from the card a this is still digital?
If it for ripped music then using winamp/foobar with APE files is tops for quaility.
The XLR will only be stereo anologue. In the set up there is an option for XLR, then you just figure where to send the playback to which outputs.
Instead of a processor, why not buy XLR power amps or XLR active speakers.
Hope this helps
Rgds
Dave