Hi jm20w,
Post #9 here has the better options and possibilities in the Mankato area that I’m aware of and there are more options in the Minneapolis area in post #2 here as well (including the 4 in the Mankato list). There are some that carry latex mattresses that are close to you in Mankato but the closest that are component latex mattress that I know of would be in the Minneapolis area.
It’s certainly possible that you could benefit from a side to side split but there are also other options and designs that may be suitable for both of you as well depending on the design of the mattress (see the first part of post #2 here). Your testing will tell you more about whether a particular mattress works well for either one or both of you than “theory at a distance”. A body pillow or a pregnancy pillow may also be worth considering while you are pregnant and can give you some of the “feel” of stomach sleeping.
Either personal testing or a more detailed conversation with an online retailer or manufacturer (see mattress firmness/comfort levels in post #2 here).
This will depend on the specifics of the cover and on how it interacts with the other layers in the mattress. Again … your own personal testing and/or more detailed conversations with an online retailer or manufacturer can be more specific to a mattress you are considering because they can all use different covers. There is more about the effects of a quilted cover with latex in post #12 here.
You can see my thoughts about adjustable beds in post #3 here which also links to the adjustable bed thread which has more information and includes some better sources that you can use as a “value reference”. They can certainly help with acid reflux (if you sleep on your back) but deciding whether it’s worth it or not or is something you would prefer over a wedge pillow or propping yourself up can only be answered by each person. I know we like ours and it was certainly “worth it” for us even though it’s not something we “need” or even use as much as some other people probably would.
I would treat the choice between Talalay and Dunlop as strictly a preference choice not as a “better / worse” choice. There is more about the difference in how they “feel” in post #7 here (which you may have already read) but your own testing or experience is really the only way to know which one you would prefer.
Phoenix