They offer a variation called the ultralight
http://www.sierratradingpost.com/sma...colorFamily=03
(this happens to be a compression version but they offer "regular" as well)
My husband and I have some similar to these:
http://www.sierratradingpost.com/sma...colorFamily=01
Lots of options at Sierra Trading Post - I get all ours there, esp when they offer a 40% discount coupon on their facebook page.
Also on STP, Icebreaker offers lite merino wool socks too
http://www.sierratradingpost.com/ice...colorFamily=03