As noted already, the trayload (rev A-D) iMacs have two IDE connectors, but one of them is nonstandard. If you're up for some very picky fabrication you can make a cable that will convert the 50 pin connector the CD-ROM drive hangs off so you can put normal devices on it. (I believe the first 40 pins of the connector are the normal IDE lines, the remaining ten include power and CD Audio.) It *may* be possible to find a 2.5 inch -> 3.5 inch hard drive adapter you could just plug into the first 40 pins, as the pitch of the connector is the same as that of a 2.5 inch hdd, but both of the 2.5 inch IDE adapters I've ever looked at had the ground pins tied together in a way which screwed up trying to use one "backwards".
I'm pretty sure you're not going to be able to play DVDs on a Bondi motherboard. It's just too slow, both the video chipset and the CPU. (With the video being the bigger problem.) I had a loose Bondi motherboard with an ATX power adapter for a while (I was planning to cram it into... something, and just lost interest) and at one point I did wire a full size DVD drive as a slave on the primary IDE channel. With VLC it could play the audio of a DVD just fine, but the video was a roughly two frame per second slideshow. It *might* of been faster if the DVD drive had been hanging on the dedicated secondary IDE channel, but I wouldn't be optimistic about it.
If you really do want to try to put a DVD drive in it on its own channel you *should* be able to use a regular laptop one, as long as you have a spare Bondi CD-ROM drive to steal the 50-pin ribbon cable adapter board from. The board *is* removable and has a standard laptop pATA optical drive connector on it.
I'm pretty sure you're not going to be able to play DVDs on a Bondi motherboard. It's just too slow, both the video chipset and the CPU. (With the video being the bigger problem.) I had a loose Bondi motherboard with an ATX power adapter for a while (I was planning to cram it into... something, and just lost interest) and at one point I did wire a full size DVD drive as a slave on the primary IDE channel. With VLC it could play the audio of a DVD just fine, but the video was a roughly two frame per second slideshow. It *might* of been faster if the DVD drive had been hanging on the dedicated secondary IDE channel, but I wouldn't be optimistic about it.
If you really do want to try to put a DVD drive in it on its own channel you *should* be able to use a regular laptop one, as long as you have a spare Bondi CD-ROM drive to steal the 50-pin ribbon cable adapter board from. The board *is* removable and has a standard laptop pATA optical drive connector on it.