This [http://www.ifixit.com/PowerBook-Parts/12-7-mm-PATA-8x-SuperDrive/IF153-092|drive] should work, and [http://www.ifixit.com/Guide/Repair/Installing-iMac-Intel-20-Inch-EMC-2266-Optical-Drive-Replacement/921/1|here's] the repair guide.
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[http://www.ifixit.com/Guide/Repair/Installing-iMac-Intel-20-Inch-EMC-2266-Optical-Drive-Replacement/921/1|here's] the repair guide, but it doesn't look like iFixit has the drive.
This [http://www.ifixit.com/PowerBook-Parts/12-7-mm-PATA-8x-SuperDrive/IF153-092|drive] should work, and [http://www.ifixit.com/Guide/Repair/Installing-iMac-Intel-20-Inch-EMC-2266-Optical-Drive-Replacement/921/1|here's] the repair guide.