QUOTE(Zymus @ Apr 6 2010, 02:19 PM)
Ok, so my plan is to use a standard 3.5 inch 1 TB hard drive,, use an IDE to SATA/USB adapter and somehow work in a DVD capability.
I'm confused as to how the USB/IDE-SATA adapter works into your plan. It seems as though you plan to plug the USB side of the adapter into an external hard drive, correct? If so, this will not work because the SATA-IDE/USB adapter is a slave device, so to speak, and so is the external hard drive. They could physically connect to one another, but they would both be looking for a host to make use of them.
As for your slot-DVD-drive idea, that sounds fantastic! It is indeed possible to do such a thing, in fact there's a youtube video of a Xbox case mod with a working one. It will not be able to read original Xbox games though, unless it is one of very few that can be modified to work that way.
Good luck with your case mod!