What is the warmest material I can buy for camping in arctic conditions?

Arctic conditions doesn't mean much. In the summer it is pretty warm in the arctic and the biggest concern are the insects, not the cold. If you are just talking about being out in the cold, goose down has the highest warmth to weight ratio. The North Face, Marmot, Mountain Hardwear, and Patagonia all make quality clothing and gear for cold weather endeavors.

Western Mountaineering makes the best (and warmest) sleeping bags on the market. a great combination of warmth and light weights. Arcteryx probably makes the best outdoor clothing on the market, with the added bonus that their stuff is light and compact. warm, and they do a great job of waterproofing everything. North Face is ok, Marmot is slightly better (but neither is Arcteryx, which you'll also be paying out the nose for). you mentioned durability, so if you're going to be walking through brambles or anything like that, you might actually be best to get yourself a pair of abrasion-proof ski pants. they're not really hard to find, and they'll be plenty warm without worry of a thorn catching on theam and tearing a seam. for your tops, layers will work great. a down underlayer will be nice and light, and then a softshell will work well to keep out a lot of the wind and also be waterproof. North Face and Marmot and Arcteryx all make both of those styles of jacket. otherwise, sweatshirts and such will do the trick. bring a bunch of wool socks and also carry a lot of those chemical foot and hand warmers. when i hike in the snow i like to take one of those warmers and put it in my shoe at the toes, and they definitely help.

I'm pretty comfortable with a Cotton/nylon blend short-sleeve, fleece pull over, then my Gore-Tex coat over that. And I'll pack in a long sleeve synthetic shirt, not sure what it's made of, but it keeps me warm. Got it at a yard sale. I'm not really sure of all the names of my gear. I've got stuff from everywhere! Like Remington, Dakota Grizzly, Coulior (or something like that), Timberland, Rocky, Wolverine, Dorfman-Pacific, Cabela's, RealTree, and some other stuff I got at yardsales that the tag is missing so I don't know who makes it. I've probably got the most random selection of winter clothes for hiking. I've heard lots of good stuff about L.L. Bean. I do not own a Down coat/jacket, but I wish I did. Anyways, this might not help a lot, but I hope it does some. Good luck finding some clothes!

hi have you checked out http://outdoorgear.net/ ? everytime I'm looking for outdoor gear stuff I always go to outdoorgear.net & they sell some great quality stuff, i have a lot of jackets & pants from them like 2 or 3 they r really durable & warm too soo i hope u find something nice!