Well, I have a good one for Platinum, but the problem is I don't have one for Black, and I can't use poketransfer right now to transfer pokemon from Platinum to Black. So, it seems to me that we have a few options:
1. You could wait until I get the national dex in Black, which shouldn't take TOO long if I use my AR too speed things up, but it will probably take until next week for us to do the trade if we use this method. On the bright side though, this will allow me to provide you with everything you want, including the Chanseys.
2. I can get you the Mews, shiny, caught in Dive Ball, with the natures and EV's you want, only lacking the movesets.
3. If you have ANY way of making the trades on a 4th gen game, that would make things much easier, as I can make the pokemon and trade them to you lickety-split.
Or, I could try to find a move modifier code for Black, but I've had little success so far.