What DAC for use with DT 770 Pro + JDSLabs O2 + SP/DIF Output ??

Well I hope the title captures what I'm looking for.  I've got the beyerdynamic DT 770 pro headphones, JDSLabs O2 and a soundcard with sp/dif output.  I'd like to combine all of this and I think what I'm missing is a good DAC that accepts SP/DIF (should be cheaper/easier/better than usb, yes?).  I'd like the DAC to be under 200$, portability is not important, but compatibility with various versions of windows is, as well as good software support.  I would consider cheaper options that were compatible and had a good record of working well.

Thanks ahead of time for any suggestions, these are the ideas I have so far:

1) Wait and get an E17 (pre-ordered out till march?)

2) wait and get a headstreamer II (backordered till ?)

3) Tube Magic D2

I ordered a fiio D3 Just to try it out and see how well it works.  I figure it will be leaps and bounds above the line out of my soundcard for the 28$ shippped (including the toslink cable).  If it doesn't work out then by that time possibly every dac on the market won't be backordered.

Windows 7 64 bit, windows xp home 32, windows vista 64, but primarily the windows 7 machine.  Using a xi-fi xtreme, which has spdif outputs.  Yeah I use my computer to do music and game not really movies.

I had considered going with the Xonar soundcard before but I like the idea of having a good headphone amp that I could use with other devices, which is why I ordered the O2; putting me in the situation of needing a dac but not an amp.