From details you give, our spec should be interesting.
http://www.silentpcreview.com/forums...c.php?p=417054
We're trying to determine if FreeBSD can support these boards. Linux support was just recently there, SB700 southbridge chip id's added to the 2.6.25 kernel series. There've also been some recent (Linux-speak here) kernel 'quirks' direct from AMD patched into the Linux kernel. We checked all of that before buying. Now someone wants to try FreeBSD though. I'm not clear yet. Just boils down to chipset support really.
Other than that question mark, our spec is what you want. AMD based, quiet, certainly cheap! Not ASUS, but GigaByte is just as good and the boards we got do come in a microATX format as well. If you go for the microATX read some of the NewEgg comments about the chipset heatsink situation; it runs hot. No such issue with the ATX format.