It's about damn time! I was looking for places to buy it when I saw this thread. What a coincidence! I did manage to find a place where you can buy the motheboard alone (533 MHz version). Check it out here.
They also have what looks to be the 800 MHz version here.
I think I'm still going to wait until the prices go down a little more.
It also look like the first barbones system on the page you linked to can accept DC input. That might be perfect.