Hi
He can sponsor you while being a student. You can choose to do outland or inland application.
If you do inland, you need to stay in Canada for 1-2 years until you get your PR, not advised to travel. You would have an open work permit within 5-6 months if all goes well (and if you applied for one).
If you do outland, it would be processed in London and you would have your PR in about 5 months (average time). You could still go to Canada with your husband on visit status to wait for this application to be processed.
Leon they are in NZ, so the application would be processed in Sydney Australia.
PMM