I've never had any health issues with my Black Sex Links although I've run into a few of those issues with my Red Sex Links in the past. For whatever reason, the Blacks seem to be hardier (perhaps it's the Barred Rock hens used in their breeding). In fact the oldest hen to ever lay eggs is a...
Alaska Backyard Chickens publishes a list of recommended breeds for Alaska at http://akchickens.org/getting-started/recommended-breeds/. If these breeds can handle Alaska's brutal winters and still be good producers, they should have no problems handling your winters. If high egg production is a...