Hi rob2121,
For reference … these are the specs of the Tempurpedic weightless mattresses as far as I know …
Tempur Weightless Supreme:
Quilt
100% Polyester Stretch MicroSuede Cover
FR Sock
Comfort Layers
2" Tempur ES Material 4.1 lb density
3" Tempur Float Material 3.8 lb density
Support System
7" Tempur Support System 1.5 density
Single Airflow system
Tempur Weightless Select:
Quilt:
Removable, washable scrollwork super-stretch cover with embossed microsuede sides
FR Sock
Comfort Layers:
1.2″ TEMPUR-ES 4.1 lbs./ft density)
3″ TEMPUR-Float 3.8 lbs density
Support System
7" Tempur Support System 1.5 density
Single Airflow system
There is also more about this type of mattress in post #2 here. These all use a very high density and more resilient “latex like” polyfoam underneath the memory foam and the main difference between them is the thickness of the memory foam layer on top.
There is more about the different ways that one mattress can approximate another one and the many variables that are involved in post #9 here. In most cases … a knowledgeable and experienced online manufacturer will be the best source of guidance about the similarities between any of their mattresses and a one of the Tempurpedic mattresses.
Outside of the Tempflow mattress you mentioned … some of the others on the online memory foam list that use a similar design (comfort layers that use a combination of memory foam with a more resilient material such as HR polyfoam or latex over a polyfoam support core) include Select Foam and Brooklyn Bedding (if you choose a combination of memory foam and latex for the two comfort layers in the Alexis although the memory foam layer would be thicker).
There may also be some similar types of mattresses available locally. One example would be a mattress like the Solace here or the Ecogel Blue Heaven here (which uses latex over the memory foam instead or the other way around) or the Denver Mattress iChoice latex memory foam mattress here but you would need to test these in person to know how close they are to the Tempurpedic Weightless Supreme.
Phoenix