Hinges: I'd say go ahead and order just one if shipping isn't too bad.
As for the rails, I think the plastic ones you picked up for my last attempt would work great for the optical drives. And then for the hard drives, the ones you show there would work wonderfully. I'd want them the other way so the tab pulls out the front of the case.
Would they be stable enough by friction or would I still want to use thumb screws?
[See Edit] Also, if you remember earlier in the planning stages I talked of getting one of these
. What can I say? I like my USB ports, front audio, and power buttons (though my current board has buttons onboard).
You mentioned that you could make a custom rail or modify the plastic ones to keep that panel from rotating. Feel free to order the black one. The cheapest I've found them was here: http://www.coolerguys.com/llbzu01.html
EDIT: Read conversation below before purchasing.Edited by IEATFISH - 5/17/10 at 9:11am