Well, I can only comment on Florida from what I read here and a few people I talked to. As for Canada, I have a lot of west coast experience both commercially and recreationally. I originally converted my JAA PPL to a TCCA CPL/ME/IR.
If you can find a suitable time of year to do it (i.e. spring/summer/autumn) I would go for Canada all the way. On the west coast especially the training and subsequent flying is a lot more varied then Florida, the airspace not without its challenges (YVR terminal area is very busy, but if you're good they'll let you in close to the bigger boys) and the flight training is almost on par with the UK (in fact I found it to be better - the only exception out west are that the navex's are a lot easier because it isn't all flat and uniform) Cost wise, I think Canada might be a tad cheaper. Do try to pick somewhere interesting (Vancouver, Calgary, Toronto - although Toronto isn't as scenic but the RT will keep you on your toes) Mountain flying is also something you could learn and British Columbia is defnitely the place for that!
Good luck!
