The amount of work this would take is unrealistic.   Character Customization works because it is many images layered ontop of each other to produce the image of your character.   However - All of the character use the same base sprite, meaning they are the same size, and each shirt fits every character.   The Poke sprites however, vary entirely in size, meaning that not only would I have to place certain items on each frame as I do with Character Customization.