The Big Kick and Big Shot are the same machine. Same size and cuts the same things. As far as cutting 12X12...the ONLY machine is the big shot PRO!!! Keep in mind the pro is about $250 or at least it was when I bought mine, and I think I got a good deal on it at that! Both the pro and the big shot can emboss thin metal...(like sheeting from Home Depot). They can cut many different materials, tin, sponge, grunge board, chip board.
Between the pro and the big shot, they will both cut the same stuff, it is the size that they differ on. Keep in mind, the pro dies (12X12) are more expensive too. But you can use regular dies in it as well. I have only seen the pro online, never in a store.