I drink beer

You said, "The imac I have uses an IDE conection to the disk drive..." I think you made a mistake there. Your iMac does not have an IDE connection to its "disk drive", it has a SATA connection to its disk drive (HDD), but that is not relavent to the question that you are asking, I think. It seems that you want to remove your "optical drive" (ie, DVD drive, not your disk drive), put a caddy in there and install a 2.5" SATA drive, correct? The interface for that optical DVD drive in your iMac is IDE/ PATA, so you need a hard drive bay to connect a SATA drive to that PATA connector. Yes, you can, relatively cheaply. I just bought one from Amazon for about $10. It is an HDE, part # N105. At Amazon, search for "12.7mm SATA HDD Caddy to PATA". I hesitate to put a hyperlink to the product, it might change. Good luck.

Steps 4~8 show to remove the wireless card from its access panel outside the computer, then steps 19~21 show to remove it from the inside once the case is off.

Redundant?