Hi Ben68,
Just in case you haven’t read it yet … the first place I would start is the tutorial post here which has all the basic information, steps, and guidelines that can help you make the best possible choice based on the criteria that are most important to you.
Im not sure where you are in NJ but if it’s northern NJ then the better options and possibilities I’m aware of in the area are listed in post #7 here. I don’t keep records of all the specific materials that each company uses in all their mattresses (which can vary between mattresses and would also be subject to constant change) so you would need to check the website or talk with each manufacturer or retailer to find out what they are using in a particular mattress you are considering. The tutorial post also has a list of the online manufacturers that are members of the site that I believe compete well with the best in the industry and many of them sell latex mattresses with many different designs, options, and price ranges including 100% natural Talalay (from either Radium or Latex International) and in some cases organic Dunlop latex as well and many of them also use organic cotton quilted with organic wool in their covers.
The design and the specifics of the materials inside a mattress and the thickness of a mattress can certainly make a difference in which mattress is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and your personal value equation but one thickness isn’t inherently better than another unless it’s a better match for your unique needs and preferences. There is more about the effects of layer or mattress thickness in post #14 here. For most people in your weight range something in the range or 8" - 9" would likely be “enough” but some would be fine with less and some may prefer more depending on their body type, sleeping positions, and preferences.
There are too many unknowns, variables, and personal preferences involved to choose a mattress based on specs (either yours or the mattress) or “theory at a distance” out of all the thousands of different designs that are available and the only two ways I know to choose a mattress are either careful and objective testing using the testing guidelines in the tutorial post (for a local purchase that you can test before a purchase) or a more detailed conversation with an online retailer or manufacturer who can use the information you provide to help you make the best possible choice out of the options they have available (see mattress firmness/comfort levels in post #2 here).
No … thickness is one of many factors that can affect the suitability of a mattress but I wouldn’t connect it with durability.
This may affect some of your online options or the shipping cost of a mattress in some cases (couriers have weight and dimensional limits that they will accept for shipping). There is more in post #2 here about split layers in case you are concerned about feeling the split.
They may have different designs but the materials they use would be the same as many other manufacturers that are in lower budget ranges. You can read more about the different types of latex in post #6 here and if you know the specifics of the construction and and materials inside any mattress you are considering then you can make meaningful “apples to apples” comparisons between them based on the materials.
I would also keep in mind that an organic certification doesn’t necessarily make a material any cleaner, purer, or better than the same or a similar material that isn’t certified. This may be particularly true in the case of latex and wool. There are also different levels of organic certifications (see post #2 here) so a mattress that is “certified organic” as a complete mattress may be no different from a mattress that “only” uses certified organic materials but doesn’t have an organic certification for the mattress as a whole. The organic certification does however add to the cost of a mattress compared to a mattress that uses the same materials but doesn’t have the same organic certifications. This would be similar to food that was grown by a neighborhood farm that you know doesn’t use any pesticides and uses organic farming methods but isn’t certified and may be healthier than some of the “organic” food that you would buy from a grocery store.
The only two manufacturers I’m aware of that make certified organic latex mattresses (vs a mattress where all the materials and latex are certified organic but not the complete mattress itself) are Organicpedic and Naturepedic but both of them also make mattresses that aren’t certified as well or that use materials such as Talalay latex that don’t have an organic certification (there is no Talalay latex that has an organic certification). Whether a consumer is willing to pay for the higher prices that generally go with the different types or levels of organic certifications is really a personal choice and like everything else would be based on the parts of their personal value equation that are most important to them.
Phoenix