Actually, you may want to look elsewhere for your RAID fix. I believe there are several competitors that beat Adaptec in that department. Take LSI Logic and Mylex, for example...
I can't complain about my AHA-2940UW, though.
Also, you may want to look at the IBM 15K drives, or some of the Maxtor(Quantum) drives, since price appears to be an issue.
Also, are you planning on running RAID 0 for streaming performance (silly, considering what a single SCSI disk can provide...) or RAID 1 for redundancy and increased read performance?