helicollege in Langley BC, near Vancouver, has a good reputation- at least as far as I hear. Haven't had any training there myself, but have flown with many who have trained there are seem more than happy with the quality of the training.
They don'y have any gazelles though - but they are indeed fun to fly. I was lucky enough to learn on one (at Her Majesty's expense, fortunately).
http://www.heli-college.com/