These vapor barrier socks are considered by many to be the nicest ones available and best fitting, but alas they are no longer made. They are designed to be worn next to skin, with your socks over them.

The Vapr Thrm Liner Socks (below) weigh 1.8 ounces/pair and fit very well. They fit my size 12 feet perfectly, with a little length to spare, and would work for feet in the size 11 to 12.5 range. Like new condition. $25 plus shipping.
The Vapr Thrm Insulated Socks (below) weigh 4.7 ounces/pair and are the same size. Also like-new. $35 plus shipping.

BPL Review here: http://www.backpackinglight.com/cgi-bin/backpackinglight/rbh_designs_vapr_thrm_socks_spotlite_review.html#.VKv9E8mjts4

No PMs please, email me direct at willi_wabbit at bresnan dot net, and include your zip code to calculate shipping.