I can't help with the PNW, but can offer some insight into the Adirondacks and snowshoes, where in certain areas snowshoes are required by law when there is more than 8" of snow on the ground.
First, most people I know do use MSR's...some use Lightnings, but most use the Evo's or Denali's. And if any climbing is planned, then any of these models with the "Ascent" option will help eliminate calf fatigue while ascending.
For boots, it's generally cold and wet here, so many use boots like Columbia Bugaboo or Ice Dragons, North Face Chilkats, or Sorels (yes, these are quite heavy). When it's really cold, some switch to double plastics like Koflach Degres. This coming weekend, since it's not too cold yet, I'll probably just wear my standard backpacking boots - Asolo Fugitive GTX's with extra socks, but in January when it can be below zero, they wouldn't work.
You may want to go to http://www.adkhighpeaks.com/forums/ and search for snowshoes...this time of year there are always posts similar to yours looking for advice, and there's some good info there.
Hope this helps - good luck!