Hi tello,
As you probably know … the Cirrus Luxe is similar to the Tempurpedic Cloud Luxe and the Regalis is similar to the Tempurpedic Rhapsody and these are very different mattresses.
There is more about the most important parts of the “value” of a mattress purchase in post #13 here which may help you make more meaningful comparisons between mattresses.
There is also more about the different ways to choose a mattress (local or online) that can help you minimize the risk involved in each of them in post #2 here.
Neither one of these mattresses have any weak links in terms of durability or the quality of the materials relative to your weight (although the Regalis uses higher quality/density memory foam) so I would make your choice based on which one you believe would be the best match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) hopefully using the testing guidelines in the tutorial post … along with a more detailed conversation with Select Foam who can help “talk you through” which of the two would have the best chance of success for your body type and sleeping style (see mattress firmness/comfort levels in post #2 here).
Based on your stomach sleeping and assuming that you are confident that both of them are a good match for you in terms of PPP … I would probably tend to lean towards the firmer Regalis because a mattress that is too soft can easily lead to alignment issues for stomach sleepers but again I would make your choice based on a combination of your careful local testing and your phone conversation with Select Foam.
Phoenix
NOTE ADDED: Because of ongoing customer service issues and delays Select Foam’s membership has been terminated and I would read the warning here before considering them.