It depends on what exactly you are looking for. A Heli Pro will hold a shovel, probe, etc, but itsn't suitable at all for actual backcountry skiing. I use mine for hiking in-bounds, and that is about it. For backcountry skiing I have a 32L BD Anarchist, and I cannot say enough good things about that pack.
So to give you useful input I would need to know whether you are doing NS "backcountry," or backcountry.