I just don't see why you would purchase two drives and spend $140 when for only tiny bit more you can get a SSD. Since you are really only looking at something like 60-80GB for a boot drive you could get a few different drives. For example there is the Kingston V Gen II drive for $155 from
NCIX or the V+ for $200.
Really I think you would be better off going with the SSD than the raid. You get better speed, cooler temps, less possible failure, and better performance. That's my 2 cents.