Two Recommendations:
Halstead in Deerfoot Meadows. Bought a natural latex mattress from them 5+ years ago. They will not lose shape or sag or anything for years and years. You get to choose your firmness , thickness, etc. It's custom made for you. 100% worth the money. You won't be replacing it anytime soon, so it's worth the investment.
Black Sheep Mattress Company -
http://www.blacksheepmattress.com/ - we bought a pillow from them and it's the greatest pillow I've ever used! I imagine their beds are just as good. Everything is made in Calgary. Well worth looking into.
Just remember that you use your bed more than anything else in your house - don't cheap out on it!