The key to figuring out what works is experimenting. Winter is tough and I went through a variety of different clothes before figuring out what works. Shoes were pretty much a non-issue for me as I use insulated boots and platform pedals. Gloves were really tough. What ended up working for me was finding a pair of oversized mittens with a rainproof (and windproof) lining that mountaineers use with a liner glove. The chest is the other important area. I picked up a softshell with a gorewindstopper and it worked great with the proper layers underneath. When its really cold, I use a down sweater and thermal underwear underneath the softshell.

I know you want to buy gear from the store you work in, but, bike clothing is not, in my experience, necessarily the best for very cold weather. Most people just don't ride in the middle of winter. A lot of people engage in mountain sports and there you'll find a better selection of gear.