Optimum RAID Config Advice Please

Hello -

I have an SQL Server 2000 DB running on a 5 year old server. It has 5 drives SCSI 10KRPM drives on IBM ServeRAID 4Lx card. I'm maxing it out to 9 on the same backplane (all 10KRPM).

Not sure the best way to make them count. Here's the particulars:

1. Current config is:
Vol1 = RAID1 for OS, swap, and Logging files.
Vol2 = RAID5 (3 disks) for DB.

2. The app does heavy writes and use of Temp DB.

I don't have by-volume stats. This stat excludes backup (taken 3 hours after a daytime reboot). Windows Task Manager shows SQL task and SERVICES.EXE both have physical reads about 15% higher than physical writes. SERVICES.EXE has about 3x the IO count as the SQL task. I assume that's mainly SQL activity.

Note: Symantec Antivirus (10.1.6) excludes .mdf, .ldf, .bak, and .trn files.

My question for you: How best to configure the 4 new drives.

Redundancy is critical, so any non-RAIDed volume is out.

Option 1:
Vol1 = RAID1 for OS.
Vol2 = RAID5 (3 disk) for app DB.
Vol3 = RAID1 for Sys DBs (Master etc) plus Temp DB. Also OS Swap. Also .BAK scheduled backup files.
Vol4 = RAID1 for all .ldf files.

Option 2: Abandon RAID5 due to write penalty (same division of files)
Vol1 = RAID1
Vol2 = RAID1
Vol3 = RAID1
Vol4 = RAID1
9th drive = hot swap.

Option 3:
Vol1 = RAID1. for OS and .BAK files.
Vol2 = RAID10 (4 disk). for all .mdf files
Vol3 = RAID1 for all .ldf files.
9th drive = hot swap.

I'm wondering if RAID1 read penalty will outweigh RAID5 write penalty (for 3 stripe RAID5). Will RAID10 advantages outweigh separation of tempDB + System DB on RAID 1 volumes (or RAID5 + RAID1).

Thank you very much for your esteemed advice. :)