Hi moose721,
There are several factory direct manufacturers in Calgary but two of them (and one retail store) are members of this site and provide some great quality and value choices in different “niches”. Both of the manufacturers will make mattresses with memory foam on request however they are both well aware of the “limitations” of memory foam itself and like many independent manufacturers are somewhat hesitant to promote it because of the widespread consumer misunderstanding about it.
The Calgary list is in post #2 here.
They are each very different but exceptional resources and I would highly recommend you call them and/or pay them a visit. They have the best combination of knowledge, service, and value in Calgary IMO.
The pricing of the memory foam topper makes more sense now … but there is no way that 6" - 7" of memory foam is suitable for anyone and you would be inviting both rapid breakdown of the mattress and back issues. Memory foam is not suitable for a support layer because in any version it is too soft and requires support materials under it to keep you in alignment. with 6-7" of memory foam … it would effectively be a support layer and your heavier parts would sink in too deeply and you would tend to be sleeping out of alignment … not to mention paying for a material that had no benefit in that thickness.
Both of you are in the lower weight range and depending on your typical sleeping positions may do best with different layering on each side of the mattress. There is no way I would be looking at Tempurpedic when there are two high quality and high value manufacturers in the city I lived in unless there was something subjective about the Tempurpedic that was important enough to pay the premium price.
Phoenix