Here is the link to one on ebay:
http://www.ebay.com/itm/19-5-Assassi...item19e025fdb5
It's not an official licensed Assassin Creed product (Wish it was) but it is almost identical to the one i have but the blade is made out of pure steel and the handel out of wood. I think this design is the one that comes closest to the tomahawk in the game
I was thinking about getting the official one, but there is just something about the design that does not apeal to me as much as this one
But that is my opinion