7 days?!......interestingly enough I am working on the same sort of project except its a Siberian Husky.....I also started a year ago & I'm currently the same age as you.....Woot!
anyway......what were you thinking of doing?....I've sort of been expieriementing with a couple diffrent ways. So far I've made one in clay so I can make a mold and cast it sometime. I also thought about building it like a mascot head but smaller. However right now I just bought a fiberglass dog head understructure from ebay...
But with the 7 day deadline I would say that your best bet would probably be to go with building it like a mascot head
http://www.matrices.net/fursuiting.asp
Or.....go to a taxidermy shop and buy one of their animal forms (sturdy styrofoam like stuff) for like a coyote or a wolf...
http://www.vandykestaxidermy.com/product/01005237/
....there is also an option for an open mouth form.....I've bought one of these as well...they're really nice