Tight fitting pants do not keep you warm. If you haven't bought a Heavy Jacket yet, try to get one with a hood and one that comes below your hips. Down jackets and full-length are the warmest. If it has a nylon outer shell, it provides good protection from the wind. Wool is a good insulator but not effective against the wind.
Leather is effective against the wind, but it is a poor insulator.
If your coat doesn't have a hood then make sure it has a collar to protect your neck. Get gloves or mittens as they keep hands warm. I suggest at least 2 pairs because one always gets lost. When the wind blows your ears get very cold. Get a scarf because you can wrap the scarf around your face when the wind blows.