UPDATE/EDIT: If it matters, I may add on a third and/or fourth GPU to the system later. Running a 1k watt PSU in the rig right now with ample space and airflow.
Do you plan to use water cooling ? How else can you fit 4 cards in one MB ? 
I would recommend mining on Windows, of course. Unless you are going to install more than 2x5970 or 4x5870
why is windows recommended over linux?
if you do your over clocking in windows and then flash the gfx bios then all voltage settings and such works in linux as well
Because [Tycho] likes Windows
