Hi teleute,
Welcome to the Mattress Forum!
You are fortunate to have some very good options available to you in the Calgary area list 
They are two separate companies that are owned by members of the same family but the businesses aren’t connected with each other in any way. Dean Halstead hasn’t been connected with Halstead Mattress Makers since well before this site began (almost 5 years ago now) and wasn’t connected with them when they became a member here.
While I do recommend the members here “as a group” and I think highly of all of them … there are also many other retailers/manufacturers throughout the industry that use good quality materials in their mattresses, are transparent about the type and quality of the materials they use, and make some good quality/value mattresses as well that aren’t members of the site (at least yet) that may also be well worth considering and I certainly wouldn’t hesitate to include other options in your research that aren’t members of the site if they compare well to the other finalists you are looking at.
There is more about the most important parts of the “value” of a mattress purchase in post #13 here which which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists (based on all the parts of your personal value equation that are most important to you).
I’m looking forward to finding out what you end up deciding … and of course any other comments or questions you may have along the way.
Phoenix