Let me start off by saying I try not to ask dumb questions that are enerally a google search away if this is one of those questions tell me you search string and I'll answer my own question.

I have a new to me Z600 12 core 24GB with an old, baby FirePro in it (V5700) if it matters. This computer is RHEL 5/6 SuSE and Ubuntu certified and has drivers available on the website for RHEL. The $99 a year for self support from Red Hat doesn't much bother me and if it's necessary I'll do just that. Folks say that Centos is 99.xx% conpatible with RHEL are things like device drivers part of what is not supported? I suppose a viable alternative could be a switch to SuSE but again how much different is Open SuSE from SLED/SLES?

Hi
I'm a fan of opensuse so that is my choice, it's easy to install and have a very good and complete administration tool named 'yast2' for easy configuration of everything you need.
Go for OpenSUSE 13.1 the newest one (3.11.xx kernel).
My choice is a workstation installation with KDE on desktop.
Don't believe it should be any problems with driver for motherboard and networks.
Choose 2GB for swap and 40-60GB for / and rest for /home.
A trickier bit is to put in open-GL support for your FirePRO graphical card to get accelerated graphic working, I believe there is a repository you can add for that.

Regards