You could try Plunkett.
http://marketseafood.ca/about/
Negotiating delivery could be an option if you make it worth their while, But you did mention that you found the minimums at City Fish too high. Back in the day David at City Fish used to deliver to us at midnight in an emergency. Richard at North Sea also went out of his way.
So it is hard to tell from your post how many tons of fish you require. and why delivery is important to you
