Make sure you check to be sure the Canidae is not on the TOTW recall list. Some Canidae products are made at the Diamond plant in Gaston, forget whether it's N. or S. Carolina.
Grains are absolutely fine for many dogs. Kibble has a filler/binder in it. If it's not grain then it's potato or tapioca or something else. That said I do rotate my foods so that my dog is not getting the same main protein or filler source all the time. Maybe that would interest you? I rotate chicken/corn; lamb/oats and fish/potato. Except the fish one is a TOTW so I need to find a new one. I see no difference in coat, energy, stool except my grain free food, the TOTW, is lower in calories and I have to feed more of it.
Is your dog allergic to the chicken? Why don't you want to feed chicken?
If the Blue Buffalo is otherwise working fine for your pup I suggest you use the protein, fat and Kcal/cup numbers as a guide in choosing your new food.