Hi hubbs,
As you know … I can’t feel what you feel on the mattress so I can only provide you with more general suggestions about which topper may be better for you and help with “how” to choose rather than “what” to choose but there are some guidelines in post #8 here which may help you decide which topper may work best or which you may prefer. It also links to some good sources for wool toppers as well (post #3 here).
Unless you have the chance to specifically test the combination you are considering … the choice of a topper will be based on your own “best guess”, your intuition and your “gut feel” about what you think will work best for you. It may also involve some trial and error. I would tend towards materials you are more familiar with and have actually tested.
Without this … I would also suggest talking with various suppliers so you can “educate” your intuition, gain some confidence about what each choice may feel like without actually trying it, and see the “patterns” that are common to their suggestions. this will give you more confidence in your choices.
Wool will add some cushioning to your pressure points (more if it is thicker vs thinner) and will tend to be firmer than most foam … especially when it compresses over time … but it’s also among the most resilient of the fibers. There’s more about this in the “wool topper” link. It’s a great choice for those who like the ventilation, pressure point relief, and overall “feel” of sleeping on a thicker layer of wool and it has less risk of alignment issues than thicker layers of foam.
Latex will usually feel a little softer and provide more overall pressure relief along the larger surfaces of the body and will have a more resilient feel than wool. Keep in mind too that if you choose latex that you will need a cover and that the sheets and protector won’t be enough by themselves to prevent the latex from breaking down more quickly with exposure to air and light.
I would also consider the refund policies of any of the sources you are considering just in case you aren’t happy with your choice and factor this in with the risk of trying a combination you haven’t tried in person.
A good “average” choice would be in the range of 2" (a “fair bit”) and you could use the guidelines to change this in the direction you think would be most suitable.
I know that it can feel like it’s just as difficult choosing a topper as choosing a mattress but the more people you talk with (at least that are knowledgeable about the materials they sell) the more you will lower the risk of choosing a topper you haven’t tried and the easier it will be to make the choice that is best for you. Without personal testing, nothing will replace talking to people who are knowledgeable about the products they make and sell and seeing the “patterns” in their suggestions.
Phoenix