Yikes- I'm still hoping to get some biking in yet

Attire- my favorite brands would be Craft and Sporthill (the Sporthill pants are a classic). But if I were you- I'd start with using your winter cycling gear, and then figure out what it is you need- in other words- if you're too hot, you need lighter weight layers or if you're too cold, you need heavier layers or more layers or a vest etc.

As far as gear goes- backcountry gear varies all the way from very much like touring gear to very much like downhill gear (and there are a lot of options in the middle). Where are you looking to use the skis? (relatively flat fields or more hilly challenging terrain?) If you're looking to use them on flat terrain- I'd suggest just using the touring gear you already have- trailbreaking is slow going- but it should be do-able in snowy conditions (not so do-able in ice/crust etc)- once you've broken the trail, you're all set until the next snowfall. If you're looking to get new gear, you'd be best off purchasing all new skis/boots/bindings. Theoretically, you can put regular bindings on the skis and use your boots, but you won't have enough control over the ski (backcountry skis tend to be heavier and it takes a sturdier boot/binding combo to put enough force on the ski to turn it).

Hope that helps.