Here are some heavyweight wool baselayers:
Filson Alaskan Long John Heavyweight Pants 21oz
http://www.filson.com/products/alask...taProduct=1011
Katmai Men's Expedition Bottom 400g/m2
http://www.minus33.com/catalog/katma...ion-bottom/709
Aclima Doublewool Unisex Longs (Here is what they say: "We claim that this is the warmest woollen underwear on the market")
http://www.aclima.no/products/doublewool/unisex-longs
Ibex ramble wool pant 360g/m2
http://shop.ibex.com/Apparel/Mens-Bo...mble-Wool-Pant