OK....here's the deal with the RAID driver...
The .img file for Red Hat 9 is not going to work with Enteprise Linux 3. The driver diskette image was compiled only for certain kernels in Red Hat 9, which are based on 2.4.20-something. The kernels in Enteprise Linux 3 are 2.4.21 based. Since the installer reads the floppy and sees that there is no matching kernel available, then this is why it throws out the message that it cannot locate any of the appropriate devices. Since there's no driver available to tell the operating system about the raid array, the installer is not going to find any drives connected to the SATA controlelr.
If there is no via raid driver diskette for Red Hat Enteprise 3 then you are out of luck getting the hardware raid setup to work....here's why:
A lot of the SATA raid controllers out there (save 3Ware) are not truly hardware raid controllers. They rely either on a BIOS function of the raid controller or a separate software driver to make the raid work. If you've ever dealt with a "winmodem" this is a similar situation.
A driver from the manufacturer is required to make the Raid array visible to the operating system.
Why doesn't Red Hat supply this driver natively you ask? Becasue the drivers, most of the time, are closed-source. Red Hat, or any other distro maker, is not going to include closed-source drivers in their distribution. If there is no source code available from the manufacturer, (which it sounds like there isn't) then you won't be able to use the diskette with anything other than Red Hat 9.
Drivers like this are also written in binary format and are precompiled to work with certain kernels...if you try to use the driver disk with any kernel outside of what's on the driver disk, then the driver will not load.
If you want the installer to see your hard drives on Enterprise Linux 3 you are going to have to disable the "hardware" raid on the raid adapter and set up software raid via the operating system. Red Hat should recognize the SATA controller without the Raid enabled.
For best results, I would download the Update 3 .iso's of Red Hat Enterprise Linux 3 WS. Update 3 has a lot of expanded Serial ATA support included in it. If you've registered your product already, go to https://rhn.redhat.com
and log in. From there locate the "Channels" tab and click on it. On that page will be a link called "easy isos" on the left...click that and you will be taken to a page with a list of operating systems you can download the iso's for...locate WS v.3 and click on it....download the Update 3 set of .isos....binary disks 1-4 are what you'll need.
I hope that helps!