It depends which part of the country - for training, Premier Helicopter Training at Pitt Meadows BC is one (speak to Rob Wood), and in Ontario, at the other end, try the Central Helicopter training Academy - Harald Sydness is in charge there. There are others, but I have personal experience of those.
As for operators, they are all pretty much OK, except for one or two. You will hear about them when you get to a flight school.
As for immigration, there is now a set period after which they chuck you out. Not too sure of the details, but pilots are no longer on the immigration wish list (yet ground instructors seem to be. Go figure).
phil