Thanks. I am here to help. Raid setups are often thought to be expensive. That has alot to do with scsi drives and external raids. Do some digging and you should be able to get a 160gb raid 0 for less than $200. That is internal of course. It is just as effective though. You do not need a "raid" card, just an sata card. You would use a software to create your raid. You can use OSX's or SoftRaids. Now if you are going to use os9, you will need the SoftRaid. Apple's software raid is not recognized in os9. I love mine. It is super fast and really 160 GB is plenty. I have 50 used for storage and I edited one and a half hours of footage this past weekend. I still had plenty of room. Most people think that you need multiple 300 gb drives to make a good video raid. That is just not true unless you are editing feature films and are using raid 5 or above. Hope this helps you out-my two articles should help inform you also.
Thanks for the brownie point!