Well, no matter what anyone says, raid 5 is alot faster than 1 or 0, 0+1, maybe 0 + 0 ,seem as fast, but,there is no way you can have a raid 0 compete agaisnt say a hardware raid 5 in like 5 disks. It is reading from 5 disks at once, and compiling it on the bus. Try this one
Adaptec 5805. Looks decent.
Acer 5920G ( Stock Air ) no OC:P
At least its DX10!