I'm ordering my MacPro next week and had a few questions about RAID setups. My Idea is to have two WD 500GB Drives in a RAID (1 or 0) and two WD Raptor 150GB either in RAID (1 or 0) or as the first as my system drive and the other as my scratch disk. Any comments on which would be best? Or does anyone else have some good suggestions?