Pretty simple, really. If you truly have to have that watch by next May, then your odds are not great IMO. You're now at the mercy of the secondary market and will have to pay the going rate. That's actually not as bad as it sounds, b/c you can always buy the watch @ market value and if, by some miracle, the Pepsi does come in, well, you won't have any trouble selling the one you purchased grey.
But wait...there's another option.
Have your wedding without a thought in the world about what watch you're wearing- really, believe it or not, there are quite a few people in the world that do just that.
And then continue to wait for the watch you want.