Do the license wherever you're planning to work, if you want to work in canada get the Canada CPL. Do you have a work permit lined up though? Very unlikely any company would sponsor you to work for them in the aviation world, you'd need to have that figured out first.
For jobs, you'll generally need >1500 hrs to land a turbine/jet job in canada, be prepared to work the ramp or head up North to get the hours in for the first few years. If you want to stay in civilisation instructing is the other route to the hours.
As for converting the UK PPL to Canadian PPL, this is easy. Just go write the PSTAR exam at a flight school and you can apply for a Canadian PPL "issued on the basis of UK license". You'll need to keep your UK PPL valid and current after this. But you can then start training for your Canada CPL with this in hand. Once you pass your canadian CPL flight test the condition of keeping your UK license valid is then removed.