Thanks for the tips! Just to add, the rig will be used for nothing but mining and I haven't decided on an OS yet.
If you are really new at this go with windows and dont use Windows XP! It doesnt support that many cards. If you are experienced with command lines or are willing to learn use linux.
I've worked with a handful of linux distros and I'm comfortable with the command line. However, I do have a spare Win7 64bit license laying around. I just want to use whatever will be more efficient/has the best applications to do the job.
Thanks again people!