uhm, I would advice you as a lot of users does so many others asking for the same question to make a functional version of the engine before asking for models.. Modeling like programming takes time, and people dont want to waste it on something they know this little about. If you had a fairly finished engine however, showing off cubes as the zombies etc. You would probably encurrage people to model for you, since then it might be belivable that the game will see the end of its alpha and beta phase.
As for now, I've made a model which I've posted here before that people can use as standins till they've got a working engine.. it does not have any animation though I'm afraid.. but I might think about adding that.
http://forum.thegamecreators.com/?m=forum_view&t=52651&b=3