Hi calderon,
Unfortunately there are too many unknowns, variables, and personal preferences involved for anyone else to know which mattress would be the best match for someone else in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on specs (either yours or a mattress) or “theory at a distance”. The most reliable way to know whether any mattress is a good match for someone regardless of any health condition or injury would be their own careful and objective testing using the testing guidelines in the tutorial post (see mattress firmness/comfort levels in post #2 here).
When you can’t test a mattress in person then the options you have available to you after a purchase to either make changes to the mattress by rearranging or exchanging layers or to exchange or return the mattress itself would become a much more important part of the “value” of your purchase so that you can use your own sleeping experience to decide whether a mattress is a suitable match for you with less risk. A mattress that is “perfect” for one person that has a slipped disc may be completely unsuitable for someone else with the same condition to sleep on.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful “value” comparisons between mattresses.
The Natura Tropical mattress at Costco is the same as the Twilight mattress listed on the Naturaworld site here. These are all high quality materials and there are no weak links in the mattress in terms of durability. Only your own testing or experience will be able to tell you though whether this would be a suitable choice in terms of PPP though and while Costco wouldn’t be a reliable source of guidance … they do have a good return policy so you can use your own sleeping experience to decide on whether it’s a good match for you and whether to keep it or return it.
This is a very different design and would be very much of an apples to oranges comparison with the Natura. There is more about comparing a latex support core with an innerspring support core in post #28 here but it will really come down to personal preference. They appear to provide a choice between a gel memory foam comfort layer and a Talalay latex comfort layer but if you were to choose the Talalay latex then there would be no obvious weak links in this mattress either as long as the polyfoam that is quilted to the cover is in the range of “about an inch or so”. If it’s two inches or more then I would want to know the density of the quilting layer (see the guidelines here). This also uses a polyfoam edge support so I would want to know the density of this as well … especially if you tend to regularly sit on the side of your mattress (see post #2 here about innerspring edge support).
This appears to be a two sided memory foam mattress which is unusual and it may have a firmer and a softer side so you can choose which side you would prefer to sleep on (they would be able to confirm this). They don’t list the quality/density of the layers though so I can’t make any meaningful comments about the quality of the materials or whether there are any obvious weak links in the mattress. There also appears to be a mistake in the description because the middle support layer would almost certainly be polyfoam not memory foam (which isn’t really a suitable support material in a mattress).
If you can find out the quality specs of this mattress (see this article) I’d be happy to make some comments about the quality of the materials and whether there are any obvious weak links in the mattress.
If the Flou gel memory foam turns out to use high quality materials and you can confirm that there are no weak links in the mattress then the choice between latex and memory foam comfort layers would also be a preference choice and there is more about the differences between them in post #6 here but it will really be a matter of which type of material your testing indicates you tend to prefer.
Once you have eliminated any mattresses that have any weak links in the design or materials and/or that you aren’t sure would be a good match for you in terms of PPP (or that don’t have a good return or exchange policy if you aren’t sure) and you are down to finalists that are choices between “good and good” and there are no clear winners between them, then your final choice (see post #2 here) will really be a matter of “best judgement” based on all the objective, subjective, and intangible parts of your personal value equation that are most important to you (including the prices of course and the options that you have available after a purchase if it doesn’t turn out to be as suitable for you as you hoped for).
Phoenix