I'm using a Wavelength Brick Silver and a MacBook laptop as a transport. An external HD rounds out the "system". BTW, the MacBook is silent, but the HD has some noise which I have been able to muffle.
I sold my Wadia 861 for the DAC and MacBook. I not only gained the convenience of being able to instantaneously select from 1,000's of tunes, I now have a multifunction device (laptop) that functions outside the audio room, and I didnt downgrade sonically. An overall win, win. Now, if I ever want to upgrade, I only need to change out the DAC, which was a heck of lot less expensive than the Wadia it replaced.
BTW, if you're seeking more information re PC Audio, try the Computer Audio Asylum
http://www.audioasylum.com/forums/pcaudio/bbs.htmland the HeadFi Forum:
http://www.head-fi.org/forums/forumdisplay.php?s=0ab121c720ce2e1e3e27400baf539bb4&f=59