Hi Crab Rangoon,
The first “rule” of mattress shopping (or topper shopping) is to always remember that you are the only one that can feel what you feel on a mattress (or a mattress/topper combination) and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or topper or combination of materials and components would be the best “match” for you in terms of “comfort” or PPP (Posture and alignment, Pressure relief, and Personal preferences) or how a mattress or mattress/topper combination will “feel” to you based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing (using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
While it’s not possible to make specific suggestions because of all the many variables involved that are unique to each person and your own experience is the only way to know for certain whether any mattress/topper combination will be a good “match” for you in terms of PPP … there is more information about choosing a topper in post #2 here and the topper guidelines it links to that 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 as well.
I would also keep in mind that ILD is only one of several specs that makes one material or topper feel softer or firmer than another (see post #4 here) and the ILD of different materials or different types and blends of latex also aren’t directly comparable to each other as well (see post #6 here) so I would make sure that you choose a knowledgeable online supplier so you can have a more detailed conversation with them that can help you compare the firmness of their toppers to other types of toppers or types and blends of latex that they are familiar with. When you aren’t certain whether a specific topper will be a good “match” both for you and the mattress you are using underneath it then the return or exchange policy can also become a more important part of the “value” of a topper purchase just in case your choice doesn’t turn out as well as you hoped for.
There is more information about wool toppers and how they compare to various foam toppers (at least in very general terms) in post #8 here and in posts #3 and #6 here and there are some additional comments about wool toppers and a list of some of the better sources I’m aware of in post #3 here.
Phoenix