in my experience with boot fitting, 32, flow and burton tend to be on the wider side (i believe they all use a D width standard but i could be wrong). Defiantly nike, ride and DC would be narrow brands not good for wide feet. Also note that if ur feet hurt while riding it could be problems with your arch or shape not necessarily the boots.
How wide? Mine are slightly wide, E instead of D, and I know I'm having a hell of a time finding proper fitting boots. I currently have a pair of Salmon F20s, but I bought them too small (length), but the width is good.