Hi Adrian,
There are many good FTOs to train at in Canada - you'd first want to narrow down which part of the country you want to be in.
Secondly, you need a Student Visa from the Canadian High Commission in London (not diff to get) to study in Canada on any course longer than 6 months.
If you do CPL and then FI rating you are then entitled to remain in Canada temporarily to work as a FI. Following that you may be entitled to apply for permanent residence if you get a full-time instructing job.
[See Citizenship and Immigration Operations Memorandum VEC E08
Effective January 4, 1999, Foreign students who obtain their commercial pilot's license in Canada and receive offers of employment as flight instructors, may train as instructors and work in Canada for up to one year post training.]
Permanent Residence is a completely different application, which according to the currently published statistics from London, can take between 29 and 44 months to process.
If you get a job offer, which has to be confirmed by Human Resources Canada, you can use that as part of your application towards gaining the number of points (currently 67) you need to qualify as a Skilled Worker.
As long as your employer will support your application, you may be able to get a temporary work permit to allow you to work in Canada during the processing period of your residence application.
Currently this application must be made from outside Canada, though this may change with the possible introduction of a new in-Canada process in 2007.
<http://www.cic.gc.ca/english/study/index.html> will give you the info about studying in Canada.
<http://www.cic.gc.ca/english/skilled/index.html> will give you information on the Skilled Worker Programme.
Hope this helps.
Andrew
[Dublin-based Canadian PPL]