Bolt cutters can bypass most pad locks. Schools keep them around for this reason. Security is part technical and part human. Really they don't even entirely need locks (like the member shelves at Noisebridge) locks just make it obvious that the stuff is off limits.
As far as where to put them. Maybe clear out under the enlarger, or clear out the stuff along the wall opposite the shelves in the closet. there are a few abandoned projects, and big, unusable items that we could get rid off.