I would start by contacting the guide services that run trips on Denali and ask them what they use. From what you have said, you are looking for an expedition mountaineering tent. If so, I would look at Bibler (owned by Black Diamond), Integral Designs, North Face (VE-25 or Mt. 25), Mountain Hardwear or something similar.

I'm only personally familiar with the TNF Mt. 25, but the others all make serious mountaineering tents. The Bibler and ID tents are single wall and look similar. If you are serious about high altitude mountaineering, I wouldn't buy anything that hasn't been used for expeditions on a regular basis. I've got a five pole double wall tent that looks similar to the Mt. 25, and is fine for winter in places like Yosemite, but I'm not sure it could withstand 125 mph winds.

You may want to ask on climbing forums like www.summitpost.org and see what people who climb big mountains regularly use. Here's a sample of what people recommend-
http://www.summitpost.org/phpBB3/best-2-person-mountaineering-tent-t56605.html
I recommend reading the other threads linked at the end of that one as well for other recommendations from real climbers (which I am not).

You might want to talk to these guys as well-
http://www.alaskamountaineering.com