That's a great Idea, some pokemon are really hard to find and to catch. I hope you could be a great breeder.
And with all the possibilities that comes from all the games (some pokemon are easiest to find in one game than an other).
I started to play with pokemon black and white. I done all the story in the two games. Just to have the twin dragon. But after I obtained them, I try SS/HG, and I forgot that I trade my dragon on my black save.
2 or 3 days ago, I talk to Hikari10 who said that B and W are best games, as I don't take time to appreciate them, I take some minutes to think about playing a new game. And trade some interesting pokemon between my 2 savings.
That was an good idea... Before I erase my black save to create a new game... Now, I don't have choice. I must do a new team.
When I'll find the connexion for my DSi, I'll send you a list with all pokemon I have on each game. So if you need some, I'll send you for free... of course.