I'm guessing that air strike quote comes from UT2004 or a similar game.

Anyway, if the two players don't absolutely have to play simultaneously, then I say go with the first two options. It would be a nice change for a Single Player level if you had to play with two players on one computer to finish it. The only thing is it might just become an SP version of the numerous teamwork levels out there like Team Foo Races. A little ingenuity would be needed to make your level(s) stand out.