There's not any/much of a waiting period for shotguns, is there? If zombies came, I'd be all set with a shotgun. I wouldn't feel very comfortable with just a handgun. I could always do some face smashing with the shotgun, and shotguns are much more dramatic, which will hopefully scare the zombies. Handguns aren't good for face smashing, they're not dramatic (unless you have awesome hand-eye coordination and can really pound the magazine in with a nice click, or if you have good revolver fanning skills, which I don't think I do). In fact, if all I had was a 9mm or something lame like that, I'd totally just throw it at a zombie and run off to find a shotgon or Victorinox Classic or something really threating.
Seeing as Sylvester Stallone is making a new Rambo movie, I think the only respectable plot would be for him to go back to Vietnam (he left a couple of his throwing knives there in First Blood Part II), at which point the zombies of the Vietnamese he killed forty years ago could all rise up and try to get revenge. He has 59 confirmed kills, and I suppose that's pretty impressive, but I think a solid zombie movie needs something more along the lines of at least 500,000 or so zombies just to make sure the viewer doesn't get bored, so I suppose that the beginning of the movie can be Rambo killing everyone currently in Vietnam (especially Gary Glitter) and then having everyone who ever died there rise from the dead. That would definitely provide enough zombies for a decent film. We also have to make sure that Sylvester Stallone writes something into the script where he conveniently loses all of his modern equipment and has to revert to his more primitive, geurilla tactics.
The other advantage to having all of the zombies fight Rambo is that we won't have to worry about that little plot twist where one of the protagonists is bitten and infected, because Rambo knows how to take care of that kind of stuff. For example, in Rambo III, when he has to disinfect a hole that is going through his entire right side, he decides that instead of using the Bacatracin provided in his PSK he'd just dismantle a bullet with one of his knives (he should also have a lot of knives in this movie, something classy like United Cutlery) and pour the gun powder into his wound and then set it ablaze. That's pretty cool.
Also, as cool as zombie movies are, I notice a severe defecit of exploding zombies. Head shots are great and everything, but Rambo would really spice things up by using those explosive arrows he always has.