Hi pooter03,
The first place I would start your research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choice … and most importantly know how and why to avoid the worst ones (including the major brands or any mattress where you aren’t able to find out the type and quality/durability of all the materials and components inside it … see the guidelines here).
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for (or that doesn’t feel as close to another mattress as you hoped it would) that are involved in each of them and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability, durability, and value.
[quote]1. Motion isolation. I rock and move in my sleep, which can wake up my wife.
2. We need a mattress that can stay as cool as possible.
3. We are both stomach sleepers, but I will also rotate to my sides.[/quote]
There is more about the many variables that combined together can affect the sleeping temperature of a mattress or sleeping system in post #2 here that can help you choose the types of materials and components that are most likely to keep you in a comfortable temperature range.
I would use the testing guidelines in the tutorial to choose a mattress that will be a good “match” for both of you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) in all your sleeping positions and for motion isolation as well since your own testing experience is the most reliable way to choose a mattress that meets all the criteria that you can “feel”.
Once you reach step 3 in the tutorial 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.
Neck issues can often be the result of a pillow that isn’t suitable for you but stomach sleepers are more prone to neck issues anyway because their head is twisted when they sleep and stomach sleeping is the most risky of all the sleeping positions in terms of maintaining good alignment. The type of materials in a pillow is more of a preference issue than a “better/worse” issue but stomach sleepers will generally do better with a thinner pillow than back or side sleepers and a thinner down pillow can certainly make a suitable choice for stomach sleepers. A pillow under the pelvis/abdomen can also be a good idea for stomach sleepers as well to help prevent them from sleeping in a swayback position which can cause lower back pain. There is more about choosing a suitable pillow in the pillow topic here that should be helpful.
Phoenix