Chuck - this mini:
http://eshop.macsales.com/Descriptions/specs/Framework.cfm?page=macminilate09.html
With Snow Leopard on it.
CDC2 - sound differences are: 2011 sounds a bit flat, uninteresting, not vivid, without weight. A bit threadbare. Also 2011 only works decent with short USB cable.
SSD I recommend is:
http://eshop.macsales.com/item/Other%20World%20Computing/Y3SSD6E120/
USB cable: I like the Revelation Audio Labs. Also heard that the Wireworld is good, but have not compred it. If you can find a used Locus Design Polestar or Axis, these are very good. Get at least 1.5m long.
As for DAC, I manufacture one, so this is what I recommend. Gets rid of your preamp without needing to go to digital volume control.
Steve N.
Empirical Audio