Hi melvy1983,
Latex in general is a very durable material but the durability of a material or component is a very different issue from the suitability of a material and component and knowing whether you will sleep well on it.
Unfortunately there is no specific material or component or type of mattress or topper that is “good for back pain” or or “good for fibromyalgia” in general because each person is unique and a mattress that works well for one person with a specific condition such as fibromyalgia or back pain may be completely unsuitable for someone else with the same conditions to sleep on. In other words there is only a mattress or topper that is “good for you” regardless of whether anyone else with similar issues or circumstances would sleep well on the same mattress and/or topper or make the same choice.
I would also keep in mind that there different types of innersprings that have very different properties and thousands of different innerspring mattresses with very different designs in a very wide range of firmness levels (this would also be true for every type of mattress category) and you may do very well on some of them while others that use exactly the same materials and components in different thicknesses or firmness levels and that have a different design may be completely unsuitable for you to sleep on. This can sometimes lead to the belief that you won’t sleep well on any of them even though you have likely only tried a very tiny percentage of innerspring mattresses that are available on the market. I would be very cautious about ruling out an entire category of mattresses that may include many that would work very well for you.
Assuming that the materials in a mattress (or a mattress/topper combination) you are considering are durable enough for your body type and meet the quality/durability guidelines here … the choice between different types and combinations of materials and components or different types of mattresses or toppers are more of a preference and a budget choice than a “better/worse” choice (see this article). There are many people that like the feel and response of latex but there are also others that have different preferences that don’t.
If a mattress is too firm and there are no soft spots or sagging in the mattress then a good quality topper can certainly be an effective way to add some additional softness, “comfort” and pressure relief to your sleeping system but the only way to know whether a specific mattress/topper combination is a good “match” for you in terms of PPP (Posture and alignment, Pressure relief, and your Personal preferences) is based on your own careful testing or personal experience on the combination. If you can’t test the combination in person then there is always some risk and uncertainty involved in adding a topper because the specifics of the mattress itself along with your own body type, sleeping position, and preferences can affect which specific topper would be a suitable choice on any specific mattress.
There is more information about choosing a topper in post #2 here and the topper guidelines it links to which along with a conversation with a reliable supplier that can provide you with good information about how their toppers compare to each other or to other toppers they are familiar with that are available on the market can help you use your sleeping experience as a reference point and guideline to help you choose the type, thickness, and firmness for a topper that has the least possible risk and the best chance for success. It also includes a link to a list of some of the better online sources for toppers I’m aware of and a link to the online suppliers that have good exchange/return policies as well.
If you do end up making a suitable topper choice and a mattress/topper combination turns out to be a good “match” for you in terms of PPP then it also has the advantage of being able to replace just the topper without replacing the entire mattress if it softens or breaks down before the upper foam layers in the mattress (the upper layers or a sleeping system tend to soften or break down before the deeper layers) or if your needs or preferences change over time and a topper can also help extend the useful life of the mattress underneath it as well. With some health issues like fibromyalgia that are often cyclical and variable in terms of the symptoms you may experience then there may not be a specific mattress/topper combination that works well for you all the time and it may even be worth considering having two different toppers where one may be suitable for you during some periods of time and the other may be suitable for you in other periods of time when your symptoms or sensitivity changes.
The choice between Dunlop and talalay is a preference choice not a “better/worse” choice. There is more about the differences between them in post #7 here but the best way to know which type of latex you tend to prefer will be based on your own testing and personal experience.
I would tend to use the information in the topper guidelines I linked as a reference in terms of thickness and firmness.
You can see my thoughts about airbeds in general in this article. While any mattress can be a good match for a specific person because each person’s needs and preferences or the criteria that are most important to them can be very different … in general terms I would tend to avoid them unless there is a very compelling reason that an airbed would be a better choice for you in “real life” (outside of the many “marketing stories” that you will hear about them) than the many other options or types of mattresses that are available to you.
Again though … I would always keep in mind that the only way to know for certain how well a topper will work for you on your specific mattress and whether it will be a good match for you in terms of comfort, firmness, and PPP will be based on your actual experience because not everyone is “inside the averages” that would work for other people.
The topper guidelines include a link to a list of the better online topper options I’m aware of (including for different types and blends of latex) but if you let me know your city or zip code I’d also be happy to let you know about any of the better options or possibilities I’m aware of in your area as well.
Phoenix