IDI's web site has some great deals on the hunting line of their Arctic Armour. It's what I use and it keeps me warm. $70 for a parka and pants is a good deal.
They also have the Black or Green & Yellow suits on Holiday sale for $269
http://www.idigear.com/arcticarmor1.php
The Parks has 2 layers of the insultex vs 3 layers in their fishing suits but at this price it is a steal.
http://www.idigear.com/parka.php
The pants are only a single layer but I have the bibs in a single layer and they are warm.
http://www.idigear.com/nbupants.php
