Cfitz is right. Why not connect your hard drives to the RAID controller. You don't have to use the RAID implementation; you can just use the connectors as "JBOD," or "just a bunch of disks." That way you can have up to 4 different hard drives on that controller and up to 4 optical drives on the regular IDE controller. Besides, RAID controllers don't accept optical drives - they will only work with hard drives.
Drives I Own:
Asus S520/A, Plextor UltraPlex 40TSi, Lite-on XJ-HD166S, Pioneer DVD-106S, Toshiba SD-M1712, Plextor PX-R820Ti, Plextor PX-W1210TS, Plextor Premium, Samsung SM-352B, Teac CD-W540E, Yamaha CRW-F1, Plextor PX-708A, Sony DRU-510A