Best thing I can think of doing is have some stand-offs made that are, in guessing, 3"-4" for clearence over the patch cords, with 12/24 screws at one end and a threaded hole at the other. Use those to mount the patch panels in question, then mount a blank rack filler plate on top of that. It's not really lockable, but at least its covered.
But if you have to reterminate because of a move to a cabinet...
Look into one of the 'multimedia' rack mount enclosures. They are typically for fiber, but for instance, Panduit's can take panel adapters for the RJ45 jacks. You'd have to look for a lockable one. I know many are latching, but locking might be a different story.
This way you don't have to relocate to another rack/cabinet.
Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay