The jacket looks pretty good with 20k in both waterproofing and breathability...couldn't tell if it's a shell or insulated though?
If just a shell you'll be fine keeping warm with proper layering (base layers, etc, depending on the conditions/temps you ride). If insulated, you may not need as many layers. Every body is different with how hot or cold they run.
As for the pants. Are there any on that site you linked that you like? Like with the jacket, you'll have to do the same in terms of layering - depending on if the pants are a shell or insulated and what's comfortable for you.
Look for ones rated high in waterproofing and breathability, like you said. Especially if you're sitting in the snow often. At least 10k on the low end, I'd think.
If you got the same colorway as the jacket in the link, it looks like it could match a lot of different colorways in pants if that matters to you.
Happy shopping and Merry Christmas