^yeah I think CMH would be a good call because I would imagine the group will be of a varied standard (unless by chance your dad's 15 best customers all happen to be pro skiers) and they (CMH) are more accomodating to skiers at the lower end of the sale...
Anywhere in AK would be a bad call for the same reason, plus it is super easy to get skunked on weather which isn't gonna be ideal for his guests, whereas many BC heli ops have cat-ski options on down days.
What I'd really advise is for your dad to get in touch with www.eaheliskiing.com who are the biggest and best heliski specialists in the world. they will be able to point your dad in the right direction and put together the trip, often for cheaper than going direct to the heli op.
oh and MAKE SURE you are on the trip!