Try these people http://www.bcwsupplies.com/type/cardboard-boxes
They make all sorts of storage cartons, many for trading cards. They are ideal for storing and transporting locomotives & rolling stock They also offer foam inserts to keep everything in place.
My personal recommendation is their super shoe storage box (3000 Ct). It will hold 3 items, is deep enough for higher items and 2 or 3 will fit into a plastic storage bin.
