I was still undecided on which head I wanted, so I went with the three-pack. It's the only way to see them all in person (and it's the only way to get the open-mouthed version on BBTS now). The two that I choose not to keep will be sold unopened at cost. Beats running around in circles shouting "WHAT DO I DO!?"
And there should be enough for everyone. 5,000 of each is a big number, and there are even some international retailers carrying their share of the total 15,000 too, I think. Plus, everyone who's remotely interested in this figure has to pre-order it. Even if it turns out bad, you can always cancel, so there's no reason to wait.
@swatdoc: ToyWiz has them all, but for $90 each. Shipping not included.