Do you really need 286Gb worth of space in a RAID 0, PLUS a 400GB secondary drive?!? You're going to need to rig up some decent cooling to keep all those drives from getting too toasty plus a pretty decent power supply.
700 watt PSU planned, two 80mm's in front of the hdd's, and then another 8 including 2 120mm's... not to mention 2 on the PSU, and the heatsink
what about 3 hdd's in raid 0?
Yan