Ummm yeah Chamonix. That place is the definition of ski mountaineering. You'll probably get pow, but you can also expect ice, crevasse, bergschrunds, along with avalanches to deal with. Pretty everyone I know who has gone there has worn an alpine climbing harness the whole time. Roping up and rappels are pretty standard there. You'll want snow crampons and an ice axe or two.
That said, the guides around there are very professional. Probably the highest level of guides found anywhere in the world. So listen to what your guy has to say. If you need a recommendation I can get you the contact info for Alain. He's a rather bad ass climber/skier guy who is a guide in Cham. At least last I checked he was still doing that gig. I got to put a few days in rockclimbing with him when he was here visiting a friend for a few months several years ago. Dude is solid.