Art - if that's what you really want, go with Luke's Ultralight Silnylon pants.
Also, by the way, you'll never get 34 degrees, raining, 50mph winds at 12,000'. In those situations, you're looking at hail or snow (almost always snow when it's that cold). When it's 50mph winds, you won't get rain, either - you'll get hail. Violent storms like that just don't produce rain at 12,000'. Also, the last place you want to be in that kind of situation is at 12,000' - you'll likely be moving very quickly to a more sheltered location, below treeline.
Considering 12,000', I'll assume we're talking about mountain environments in the Sierras/Rockies. Here's the storm weather patterns that happen out here:
1) warm temperatures in spring, summer and fall produce storms that come out of nowhere in the mid-40s with hail, lightning and high winds
2) cool temperatures in spring, summer and fall produce low clouds, very light snowfall/rain and minimal winds
3) storms in cooler temperatures in spring, summer and fall are VERY predictable and usually produce blizzards - unless you're a masochist, you won't be going out in such conditions anyway
I don't mean to sound condescending, but it sounds like mountain environments might be new to you? I'd suggest getting some experience in mountain storms. You'll be able to better form an opinion about what actually works and what doesn't. Rain pants would be one of the the last things I'd be bringing on a fastpacking trip.
(softshell pants or running tights and a rain skirt works very well, by the way)
If you disagree, I'd like to hear about your personal experiences that have made you think you need actual rain pants. I've found rain pants to be more of a PNW item (no experience in the midwest or east coast).