Hmm... the shoes would probably be the easiest project. You could probably cheat ang just get some black sneakers, and maybe paint a white stripe on them. Don't forget to get them 5 sizes too large!
The gloves would be harder, but maybe you could buy some gloves that are too big for your hands, then cut the tips and re-sew to make them more pointed. Then you can just draw or sew the big X on them. The keyblade, though... man, I'm not sure. That thing is pretty detailed. Maybe you should ask someone who's done it before?