This isn't so much of an open contest as sweepstakes. If any of you have ever bought Lunchables, you'll know what I mean. There is tons, AND I MEAN TONS, of fine print associated with these things. I one-hundred percent understand why it's only U.S. It probably took a hundred miles of red tape to get this legalized. An international one would probably be thousands.
Anyways, I know I'll be submitting a design myself. DJ's Century was designed in the late 24th century. It seems like the Enterprise E had a full 30 year-ish life at least a decade into the 25th, so I think even DJ will agree that the Century wouldn't be right for this timeline.