Just a small info here, I'll extend it, when I've finished testing the system.
Mainboard: MSI K9NGM3 Audio: 7.1 analog / koaxial out Video: VGA / HDMI (supporting 1080i and ui2) Extras: 6 USB, 1 Firewire, eSATA
I can confirm, that the Fiire Invisible is working out of the box. However, the Lan Option ROM had to be enabled in the BIOS. The CPU cooler is a little bit to loud, maybe this can be adjusted in the BIOS (AMD cool'n'quiet...).
I don't know why they didn't made it available, but the Board also has an RS232 port. It is located near the keyboard plug and the BIOS shows it too, so it should be usable.