I would suggest that you go to Bateel (They have several shops around in Doha) also try Mega Mart in the center and West Bay...
If not see the bakery section in Carefour, the do have some fine types of Loaf
If you still dont find what you want, then I am sorry to tell you that you'll need to bake it your self.
As to do with knifes, I do recomend you not to get one, you might mis-use it and then regret it.. :-)