Mungo,
I've a Hilleberg Akto, which is a one man tent, but Hilleberg do various ones for two men. I've been in snow, hail, rain and high winds in mine and have seen other brands perish in the same conditions. It is exceptional.
I bought it a few years ago and they have gone up in price alot since then. I looked at a cracking two man job in Keswick last week and was a bit shocked by the cost.
However, Hilleberg make expedition grade, bombproof, tents. If you see a photo of Everest base camp or somewhere similar, chances are you'll be looking at several Hillebergs.
Cheers,
Bob