Best Audio Interface for Apple G5 Computer?


I am just wanting to get my feet wet in setting up a music server. To start out I just purchased a Apple G5 Computer. I currently have a Lite DAC with a optical and coaxial interface. I have 3 questions:

(1) To get the best sound should I use the optical out or FireWire out on the Apple G5?

(2) If the recommendation is to go with the fireWire output, what would be the best recommendation for a interface to go from the FireWire to SPDIF? If possible I would like to get an interface for $300 or less (would be willing to find something used on ebay or Audiogon)

(3) Is the new Mac Mini that much better than the Apple G5 in establishing a music server.

Thanks for your help as I am trying to learn about creating a music server.
cbman
Tgrisham and Onhwy61 -Thank you for your comments they are very helpful. Have either of you used Amarra or Pure Music software and if so what are your comments regarding these programs.

I also assume from your comments that the audio quality from FireWire, USB or Optical should not make that much difference.

Again, thanks for responding to my questions as I am learning more about digital audio.
I also assume from your comments that the audio quality from FireWire, USB or Optical should not make that much difference.
Don't make that assumption.
"Don't make that assumption."

IME, the connection is as(more) important as the DAC chips or filters. In other words, I think the connection makes a big difference- depends somewhat upon the DAC though.

I would seriously consider moving into a more modern computer. I do not recall about Amarra or PM, but many of the new player programs will not run under OS 10.5 which is the limit of the G5. On my system, the player programs are very different from each other. More so than say, interconnects for the most part, unless one is particularly bad.