You can save all your screenshots really quickly if use the script in PS. It saves all your layers as separate images. Can be set for only the visible layers as well.
I've got an even better solution for that called Load Files Into Stack (File->Scripts). Just open all your baked maps and all other fancy stuff you want to combine and hit Load Files Into Stack and Add Open Files and you'll get all the (saved) open files laid on top of each other in a new document with layers named after…