[size=12]Unless you're positively in love with the idea of using hidden magnets to hang all of your cast iron that you value highly, I'd back away slowly from the notion. Here's why. A hook may be a little unsightly, but you can tell easily by eye at a glance when you have the darned thing secured and when you don't. If you get used to slapping a heavy large cast iron pan onto its flush and/or hidden magnet, you'll kick yourself the first time that you hang it back up in a hurry and unknowingly have it half on, half off, and then watch from across the room as it slowly slides the rest of the way off on its own and falls four feet onto the hard floor. Especially if it is a 14. First skillet you crack, you'll wish you had just used hooks.
Also, if you're storing skillets in stacks, it's not a bad idea to put something shock-absorbing in between each one. Paper would be OK; I use foam sheets that U-Haul stores sell to pack your dishes for moving. If you stack iron on iron, you can wind up wearing a shiny spot opposite the handle on the bottom surface of a skillet where it rubs against the inside of the next skillet down in the stack. It's surprising how little effort it takes to accidentally buff a shiny spot onto a skillet this way.[/size]