There are a few brands that offer wide sizes, Bont, Specialized and Sidi come specifically to mind. Diadora (if you can find them) tends to run wide as well.
A product review of the Louis Garneau Tri Air Triathlon Shoe. After nearly two years of testing, see how this shoe performed. Currently being replaced by the Tri Air 2.
Both the Lake Triathlon Shoe CX210TRI and the Lake Road Shoe CX225 offer distinct advantages. I tested both shoes and found them to be extremely comfortable, good looking and durable.
I started riding this spring with the Carnac shoes on Look pedals (with plenty of float). About five minutes into a ride I get sharp pain on the outer edge of my feet, just behind the pedal.
They are comfortable, but on longer runs the ball of my foot starts to heat up. I actually had to STOP, take off the shoe, massage my foot. This would help for a while, but the pain usually returned.
Whether your bike is new, new to you, or you have not been on the bike for a long time, you really should spend some time thinking about how your bike fits you.