Get a small case, some ram and a small laptop HD. You could do SSD if you wanted really quiet. Then install xbmclive, once setup, configure it to use hdmi. I have three HTPC's based on that board and they can be run fanless and with the dual core and the Nvidia VDPAU i'm doing 1080p over the network to my NAS.
I've tried the WDlive, the seagate, AppleTV, xbox360... none are as flexible as xbmclive.