Use RAID for desktop computer?
If data loss is your concern, please remember that RAID is not backup. I suggest you invest in some form of backup, whether it's a 'cloud' solution or a simple rsync job to another computer.
This way, you can have your RAID 0 for performance as well.
Be aware that even if you are mirroring drives, the raid controller itself is a single point of failure.
It may be worth considering using an SSD as the OS/applications drive, for excellent performance (see Anandtech for a review of the latest Intel X25-M drive).
I opted for this, with two non-RAID HDDs for data (plus an external drive for backup), which works well.