I've been really trying to get a Ditto with flawless, or near-flawless, IVs. I would prefer the Ditto to have any of the neutral natures, but serious is just my favorite (which is why I listed it). I would love it if the Ditto could be shiny, but I'd be able to live with it if it wasn't.
I can offer you some female Dream World Pokémon, or other Pokémon with their hidden abilities, and I'll be more than happy to give you some PP Max if you might need one. I can also provide Pokérus, in case you don't already have access to it. None of my Pokémon are flawless, or anything like that, but I'll post what I do have and maybe you'll see something fancy. I have White 2, so I can try to get you any version exclusives (since I read that you're using Black).
I have a Gentle Elgyem (M) that has Synchronize, in case you're still looking for Pokémon with that ability.
Female Dream World Pokémon