1. Did you remove the lines from the Disk1 CONFIG.SYS that try to load the AHA* drivers?
2. Did you try the OS2CDROM.DMD file from eCS?
3. Is there something like OS2SCSI.DMD or .ADD that is loaded from the Disk1 CONFIG.SYS? If so, please try updating that with the eCS version.
4. Is there any way that you can borrow an older CDROM drive (non-CD/RW or maybe even IDE--if you have an IDE controller) just to get through the installation?
5. Just a note: I seem to recall that in the Disk1 CONFIG.SYS, case, spacing and order are all really important.
I'm sorry I cannot be more specific. It's been over two years since I've done an OS/2 install.