Marmot Oracle Pant - Men's - 2009 BCS

You basically have two options here, a hardshell like these with a plastic waterproof breathable laminate affixed to the fabric, or a softshell with a high level of breathability plus great water and abrasion resistance, but no true waterproofing.

With hardhshells, it is the unfortunate reality that you get what you pay for. For super deep, wet snow, this is probably your best bet, and you should get the nicest pants you can afford. The Precip laminate on these is the bottom rung of the ladder, Membrain strata is better, and Gore Tex a step above that. From Marmot, I'd recommend the Tamarack or the Minimalist. If you can afford it, go one more step up for their Randonnee. With hardshell pants, Inseam venting is important, and I'd also avoid anything with its own insulation, for more versatility.

If the snow is dry and it will be very cold, A softshell will bead any potential water droplets while being MUCH more breathable and comfortable. Think cotton t-shirt vs trash bag (hyperbole of course but you get the point). I have Marmot's Scree, and they're incredible. The Patagonia Guide softshell are almost identical, and the OR Exum and the Stoic Tour are similar but slightly heavier weight.

I'd also have an insulating midlayer for wearing while hiking on hand, especially if it is going to be brutally cold. 100wt fleece should be sufficient, Marmot makes the Powerstretch and the Reactor, Mountain hardwear makes the Microchill.

Finally, I'd recommend a super warm pair of synthetic or puffy pants to put on over everything once you get into camp, stop moving and cool down. Mountain Hardwear has the Compressor, OR has the Neoplume, and Montbell makes a variety as well.

In total, that's four pairs, Baselayer, Fleece active insulating layer, Hardshell or Softshell outerwear, and a heavily insulated layer to put on over everything for in camp wear.

Best of luck and enjoy your trip!
Simon

If you size them large enough, you could even wear them over a second pair of Oracle Pants.