Hi, I saw your question on the forum and noticed you said you wanted both Zekrom and Reshiram, so you were thinking of getting Black and White 2 (or the other way around). Actually, it won't work that way; you'll need to get the same color, so White and White 2, or Black and Black 2 if you want both legendaries. Other than this, it really doesn't matter which version you chose in terms of continuity. As a bonus, if you're going to play Black or White first, make sure to use Memory Link in the sequel, to unlock new features and interactions (was going to give a link, but thought you might want to avoid spoilers).
// really sorry if this message bothers you though
// really sorry if this message bothers you though