Nice rig. I need to get me a DX10 card.
To add to the earlier comment about RAID0. I've been doing it for years, but I know that I can lose everything at anytime...So I backup regularly to a 500GB drive.
Also, you might event think about going to 3 drives instead of 2. The more drives the faster the speed in RAID0. Keep the drives small and only put the OS and basic stuff on there...keep your docs and important stuff on the other drive...and backup regularly.