I hope you've still hung onto your sanity...(if I'm incoherent it's because of the sinus infection and the medication I'm taking for it.)
I have a Proliant 4500 that I had the same problem with...
except the 4500 is EISA bus and Red Hat doesn't recognize the on-board SCSI controller that controls the CD-ROM either. (It does, but it doesn't..it has the drivers but doesn't look for it on the EISA bus)
What I was looking at was installing a ISA bus SCSI card to run the cdrom and one hard drive to install Red Hat on. Once it was up and running I could load the cparray.o module
dynamically or reconfigure the kernel. (I'm at work and don't have my notes, I can send you all the links later.)
Then I would put /home or other data on the now working array.
I also tried FreeBSD which also didn't like the on-board controller necessitating an ISA SCSI host adapter to run the CD-ROM, however it DID like the RAID array and set it up without a hitch.
I am currently running Novell Netware 5.1 on it, which likes everything, even all 4 (blazing fast 100 mhz) processors. Linux won't run all four, but FreeBSD will, if you recompile the kernel. Something about these early multiprocessors being pre Intel specification. (again, my notes are at home) I hope I helped some.
At your service,
Potpourri