I'd go with the Tangela or Shinx personally.
I've been using my other DSi to trade from Black to White. I usually play both on my White DSi, which is the one I registered both my games on for Global Link. I had my Black in my other DSi in order to trade with my White. My Black is telling me the Game Synch has run dry, even though now its been more than a day since I used it. I assume it has to do with using a different DS. I heard that screws up the Game Synch. Can anyone confirm this or is it just some kinda glitch?