I wouldn't even consider neoprenes anymore. Breathables are superior waders.
I use bootfoots in the winter and the water can often be in the mid-30s. If you need more warth, simply wear more clothing underneath them. It doesn't matter whether you have your insulation under the wader or rely on the wader to provide some insulation itself (neoprene). Water pressure can compress your clothing so try to wear something that wont be so affected.