ORIGINAL: freezermeat
If you can get to a military surplus store, try and find what are called "Mickey Mouse" boots. these are designed for use in Antartica, and cost around $80. they are pretty bulky but extremely warm. just a suggestion
We actually called them "bunny boots." The old style were large and white, but you may be able to find the newer versions that are quite a bit smaller and also in black. I have not yet run across a pair, but would buy them in a heart beat if I did, as they are awesome for very cold weather.