I have my second drive ready and an external housing for the optical drive. I do not, however, have the adapters to put the drive in. I live off-shore and it's hard for me to get a hold of stuff like that. Soon though!
So- I'm sorry but I'm slow on this...
If a second hard drive is connected to the CD-ROM plug (via the enclosure & conversion plug), the 9x00 will simply detect it as (for example-) IDE 1, primary HDD slave, all on it's own?
I assume the converting plug has the master/slave jumper "built in" and taken care of?