I would absolutely LOVE to have Beldum, or any in that evolutionary line!
In return, I've gotten pretty decent at IV Chain-Breeding. If there's a perfect Pokémon you want that I can get, please let me know (I play Pokémon Y only though, need to save money to purchase any others).
I can get you a beldum!
I don't know much about natures, or if you're wanting a specific type. Just let me know and maybe we can work something out!