WOW that's a lot of unknowns.. your system must be fairly new. Have you considered running Debian Testing (Lenny) instead of Debian Stable (Etch) ?
First thing I would try would be to update the pci.ids looku-p table to see if the systerm can then recognize your hardware.
In Debian that can be done with the command : update-pciids
User@it-etch:~$ su -
Downloaded daily snapshot dated Tue 2008-09-16 01:05:02
Give lspci another shot and see if it does a better job of detecting your hardware.
MMmmmm that;s a nice looking piece of hardware.. I see that it supports RHEL WS v5 (64) so you should be able to get Debian running on there. Debian Lenny has a newer kernel and is more up to date, which is why I suggested you might want to give it a try. It should be the new stable version in a couple months.. I think