I'm on board with BTBowhunter... Neoprene waders are very hot... Not sure what you plan on using them for but both Simms and Orvis make top end breathable waders ($ 400- $ 500) as well as lower priced models ( $ 100 - $ 150) that work great in the summer and layered up underneath in the winter.

If you are only going to use them in the winter, Neoprene will be fine. But if you are going to use them in warmer weather; and need to walk any kind of distance to get to the water; you will really want the water to be cold once you get there.

Good luck.