I wear the Klim Free Ride pants and I have a pair of Togwotee bibs. Both are great but I find myself in the Free Ride pants way more then the bigs though.
I also wear a Tekvest and don't care for the top portion of bibs when worn with a Tekvest. For me, it's too hot and not quite as comfortable, when compared to pants. With the pants, I also utilize the Klim suspenders, which keeps them up and haven't had really any issues with snow coming in.
I would second going with shell style, uninsulated and just layer!!