Hi ninjab,
Just in case you haven’t read it yet … the first place I would start your research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choices.
Unfortunately there are too many unknowns, variables, and personal preferences involved for anyone to be able to predict which mattress would be a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on any specs (either yours or a mattress) or “theory at a distance” so if you can’t test a mattress in person then a more detailed conversation with an online retailer or manufacturer so they can help “talk you through” the options that have the best chance of working well for you can be one of the most important parts of a successful online purchase (see mattress firmness/comfort levels in post #2 here). A knowledgeable and experienced online manufacturer or retailer will know more about their mattresses and how well they are likely to match different body types and sleeping positions or other mattresses than anyone else.
Having said that … the tutorial post has a link to a list of some of the better online memory foam options I’m aware of and many of them make mattresses that are close approximations of some of the Tempurpedic lineup that include the Tempurpedic mattress that they are designed to approximate in the description. Even for those that don’t have a specific comparison in their description most of them would be familiar with the Tempurpedic line and can give you good guidance about which of their mattresses are closest to any of the Tempurpedic models that you prefer.
There is also more about the different ways that one mattress can “match” another one in post #9 here.
Based on their description and on forum feedback this would be closest to the Tempurpedic Cloud Luxe.
They don’t make a specific comparison with this mattress to any of the Tempurpedic lineup but they do say that it’s a firmer model so it would likely be closest to some of the Tempurpedic mattresses that are listed as being in the “medium firm” range. They would be able to tell you more with a phone call.
Their description says that this is an approximation of the Tempurpedic Contour Signature.
As you mentioned … they compare this mattress to the Tempurpedic Rhapsody Breeze.
There are also some others that make specific comparisons to the Rhapsody Breeze or the Rhapsody Luxe on the list as well including (off the top of my head) …
http://www.brooklynbedding.com/memory-foam-mattresses/cool-symphony-memory-foam
http://www.brooklynbedding.com/memory-foam-mattresses/purecool-symphony
http://www.selectfoam.com/cat-regalis-luxe-coolmax.html
http://www.tempflow.com/copia-mattress-model.htm
Phoenix