It is against Project Pokémon policy to help get hacked Pokémon through the Pokebank. However, for getting Pokémon to Black/White 1/2, you either need an Action Replay, or any combination of devices discussed in this guide.
As far as 2DS vs 3DS, it doesn't matter. A 2DS is simply a 3DS in a different casing without a 3D screen.