Try a web search for heli-skiing and Banff and you'll find the local operators. Most use 206s so you might be tight for space and weight... You'll also be at the mercy of the weather. If it's snowing, you ain't flying.
Banff isn't a ski resort though! It's a resort town with a couple of ski hills nearby - Sunshine and Norquay. It's only an hour's drive from YYC so hardly worth the trouble of a helicopter transfer. Besides, you really need a car to get to the slopes (about a 20-30 minute drive depending on your hotel) so why not just rent one from YYC? If you really must have the helicopter, your hotel can probably help.
Some hard-earned advice - don't leave ski boots in your car overnight! I did that once in Banff and I couldn't get the darn things on the next morning - they were frozen solid.
