Actually, there's a post that was stickied that tells you which enemies drop what and where you can find them. Just go to KH2 help and find the sticky of it.
Also, if you don't want to have to complete the synthesizing, then do it on Proud Mode, where you only have to completely beat the worlds. You don't have to finish synthesis on there.
If you don't want to do either, then just look it up on YouTube.