idruthrbfishin

I would also go with the 400 gram boots, but would also recommend using a thin polypropelyne liner sock under the wool sock. I've used this combo for yearsand have always had good luck with it. The poly liner socks wick the perspiration away form the skin and will keep you much warmer. As mentioned above, remember that if your boots are too tight, you don't have a chance of staying warm. Good Luck!
P.S. I used Rocky boots for years, but recently have had a lot of trouble with the soles coming apart in large chunks.... food for thought.