The child locks more or less have a small bar the you attatch inside the cabinet. Then on the door you attatch the hook in the picture in the link, the hook is spring loaded to stay in the locked postion which clasp to the bar you installed inside the cabinet.
The magnet "key" is a fairly strong magnet that actually over comes the spring allowing the hook to let go of the bar.
I don't think the plastic piece on the outside of the caninet where the key goes to open the lock is needed, I think it is just a guide, but I am not certain about that.
I think if you have a large panel you would need several of these latches to make them work.
Personally I would probablly use magnets all the way around, and then add the security latches in the four corners to prevent the children from pulling the panel off on accident.
Another option, and I think what MThompson had in mind, would to make a hook and groove type set up along the bottom, and put these clasp at the top, so you "unlock" the top, and then have to lean it back and up to disconnect the bottom.