not sure I understand what your looking for?
You want a Linux Distro that supports Opteron 64bit?
Gentoo have itianium/64 support.
Is there a compiler available for Opteron you can use?
http://www.linuxia64.org/
-nox
I found that I needed to be root to mount an NTFS drive (partition).
One doesn't need to log in to root to become root, just su.
then try to access the mount point.