I can give you some info on Canadian helicopter schools on the west coast (just PM me). You'll be talking about C$45,000 for a commercial license here.

Bizarrely, per hour, commercial training for helicopters in the UK is a little cheaper -- I am at a loss to explain why helicopter training is cheaper in UK, when fixed wing is more expensive there (I've done both).

That said, the number of flying hours required in the UK for a commercial helicopter license is higher than Canada, so it'll end up costing you more regardless.

Private flying licenses in UK, or US or Canada, can be exchanged with a simple bit of paperwork for private licenses in other countries. Commercial licenses require, I believe, flight and written tests in the new country, but all the training in the prior country qualifies (though I believe there is slow progress towards making them fully exchangeable also).

KP