I got an e-mail back from 40 below in response to my request for more info on the foam vest. Vest weighs 18 ounces and has foam on the back only. Looks like they are aiming at the cold weather market. Still not quite what I'm looking for but heading in the right direction.
"Hi Daryl, Thanks for contacting us! Are you heading somewhere cold soon? Sorry that the vest is not on our website, we are fixing part of thewebsite, and it will be back on soon. Here is a picture and some information: The "FORTY BELOWR VEST*"A truly revolutionary clothing piece! The Forty BelowR Vest is great forfolks who sweat a lot and are trying to reduce moisture buildup in theinsulating layers between your back and the backpack. Designed as a "zonevapor barrier" to keep perspiration moisture from accumulating in the layersof clothing between you and your pack. Ever take your pack off to find anexcess amount of water in your back insulation, only to quickly turn to ice?This vest will help eliminate most of this problem. Wear The Forty BelowRVest* on top of a synthetic underwear layer and then layer your insulationon top. The Forty BelowR Vest is best suited for long trips in extreme coldconditions. When you are done with your activity, you can take off the vestand freeze-dry the perspiration off the inside back. Moisture that will bein your base layer is much easier to dry than to try and get it out of athick fleece or insulated jacket. Use this vest also as a sit pad or extrainsulation under your torso while sleeping. We also use it for watersportsactivities, as it is a great way to add insulation under a PFD. The back isa thin neoprene foam that is rubber on the back side, and nylon on theinside. The front of the Forty BelowR VestT is made of a medium weightsynthetic fleece material that is warm yet allows moisture to wick well anddry fast. Two front pockets, a heavy duty zipper, shorter cut in the frontto help keep out of the way of hip belts and climbing harnesses, longer cutin the back to help insulate the lower back."...anyone who has carried a pack and sweated and soaked their insulation,which then froze or didn't dry should realize what an advantage this radicalproduct could be in your climbing wardrobe. I give it a 9 on a scale of 1to 10" Marc Twight Rock and Ice magazine Product Review, February 1993SIZES: S, M, L, XL,XXL. Weight: 18 oz. size Medium. Please let me know if you have any questions, etc! You can order the vestby calling us, or placing an order on our website by ordering a "t-shirt",and we can manually adjust your order and we do not charge your card untilwe actually ship the order. There is a place you can put that the order isfor a vest in the Comments box of the check out pages. Joel AttawayForty Below, LtdP.O. Box 39Graham, WA 98338 USATel: 253.846.2081Fax: 253.846.7853www.40below.com"