Definitely Toronto is bigger than Calgary. If you are in Petroleum, Minning, Construction and Heavy Machinery .....go fo Calgary. If you are into Banking, Finance....I would say Toronto.
Keep in mind though, Calgary is reeling under low oil prices. So lot of layoffs and cutting down going on right now. If you already have done the P Eng certification in Canada, thats great. Otherwise get going immediately......
As for Medical degrees from foreign countries is concerend, its a long road ahead of you. Although I speak from only two interactions, one with MBBS from Srilanka and other Dentist from India. Both driving cabs now. There is shortages of Doctors here, for foreign graduates to break into Canadian system looks like a big task.
