You could pick up a binder and some of those clear sleeves for keeping papers together (all of a sudden can't think of what they're called, lol), put them inside the sleeves and you'll still be able to see what they are and they won't spill all over the place.
I've only used CTMH acrylics, so I'm not sure if they all come with the plastic backing that you stick them to that has the picture of what the stamp is? But if they do, just put the whole thing in a sleeve...easy as pie.