HI Danmanhoogs,
Welcome to the Mattress Forum! 
You’re certainly considering something using good quality and durable materials (latex). And personal testing will be the most reliable indicator of the comfort that both you and your wife prefer. And as you’re considering a component-style system (like at Arizona Premium that you mentioned), many of these are available with split configurations, as you’re already aware.
As you’re in the Vancouver area, you can perform a forum search on Vancouver and see what other businesses have been discussed in that region which may be helpful to you. There are no site members in Vancouver, but you certainly have quite a few mattress shopping options in your area.
Whatever business you’re considering, I would always confirm that any retailer or manufacturer that you wish to visit is completely transparent (see this article) and also make sure that any mattress that you are considering meets the quality/value guidelines here.
If you have any questions about specifications or certain products you discover, feel free to post back on the forum and I’ll do my best to be assistive.
And regarding your temperature concerns, there is more about the many variables that can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range.
I’ll look forward to your updates.
Phoenix