That wasn't my neck of the woods when I lived there, but the major grocery store chains in PHX are Frys, Albertsons, Safeway, and Bashas. Frys is part of Kroger so if you already have a frequency card for one of their chains, you can use it there. A quick search of their websites should yield something for you. I would recommend looking around Bell Rd. or Union Hills Rd.

AZ is 3 hours behind Eastern time until fall.

I hope you enjoy Flagstaff--that was my home for college and a year after. You should definitely go to Lowell Observatory while you're there.