I did the first half of the season with panaracers that were 35's. They were fine except in the few muddy spots I ran though (most notably, at Bartlet). I switched over to Michelin Mud 2's that, I think, are 32mm wide. They seemed fine in just about any condition.

Go with the 35's unless you have problems. Even if they're bad, I doubt they'll cost you more spots than beginner technique or cyclocross skills will. If you don't like them after a few races, switch them out.

For us Cat4 types, tire pressure is probably more initially important than tread pattern.