Whatever you wear, you want to make sure it fits kind of loose. This will allow for the warmth your body puts out to circulate underneath the layers of clothing. To tight and the warmth is contained, therefore it doesn't circulate. When temps are below 40 degrees, I'll wear fleece lined jeans, thermal top, t-shirt, medium duty jacket, waterproof insulated boots, knit stocking hat and gloves. Over top of all of that I wear a BPS 100 mph suit, for wind and moisture protection, but any type of wind/moisture resistant shells will suffice. Ideally, you would want some type of polypropylene base wear to wick away sweat, especially if it's cold and humid. The whole goal is to create an insulated, loose cocoon around your body to allow your bodies warmth to move around, sort of like an oven. I have been on the water with temps in the mid 20's wearing this set up and remained comfortable the entire trip

.... I've been comfortable in 28 deg. temps/25mph winds with this. not catching any fish, mind you, but comfortable