For the PNW....
I recomend that you buy your self a pair of breathable waders. I have been breathable for about 10 years. If its really cold I just wear another layer of some high tech pile clothing under the waders. I must admit that an average day of fishing for me includes from 3 to 12 miles of trail hiking so neoprenes is totaly useless for me. The breathables are widely accepted as the perfered choice by the vast majority of anglers here in the PNW.