My understanding has always been that wider tires are going to be more comfortable and used more for bumpier drier courses where skinner tires are going to be a little better on muddier courses. Opposite of what many people would initially think.
I agree with Katsu. 32s are your safe bet. We have a guy on our team that runs 34s, but he's a big guy that races in the pro mountain bike circuit so he's used to more cushion under him. I'm a smaller roadie and I prefer the handling of the 32s.