As for that deal, just get a normal 2DS plus a game. Register them to Club Nintendo, and you'll get a free download code for X or Y. Two games already for what it would normally cost anyways.
...unless that deal nets you BOTH X and Y. Download Pokébank, and you won't need more than 1 2/3DS to transfer anymore! (You're screwed over with Pokémons who evolve by trade though haha)