That's right. If you do not plan to compile yourself, then
the linux_xorg7.tgz package is the way to go (openmotif
libraries are statically linked). And as Donna reinforces,
it is likely that any Linux OS will work fine, as you just
need the ability to find dependancy packages (I have never
found a Linux version that I couldn't get AFNI to run on,
having tried RH, Fedora, Ubuntu, SUSE, and FreeBSD).

Donna's suggestion of support is a good one.

I get nVidia's drivers via rpm.livna.org, as that is done
properly via yum (so dependancies and versions are checked).
If you get drivers directly from nVidia, you may need to
re-install them every time you update the kernel, as they
need to be compiled to match the kernel version.

- rick