If you want to use RAID make sure that forst of all your motherboard supports it.
Also if you are going to set RAID up make sure you go for 'Mirroring' type and not the 'Stripe' mode.
The Mirroring mode makes a backup where as the Stripe mode spreads the data over the TWO drives meaning if ONE of the drives fails you lose everything. Not nice!
Have a read of further info at click here