It really shoulsdnt mater what brand you get for RAID, oh, cept for the actual seek times. Remember that you are reading and writing to multiple disks at once. The more the disks, the faster the performance. I would look at sustained throughput, cache size and seek times. Just make them all the same, or very similiar.
Acer 5920G ( Stock Air ) no OC:P
At least its DX10!