Hi Optic,
Baybed has custom built mattresses so you would need to call them to talk about and choose the layers and components that you want and then they will ship them anywhere across the country.
The better options and possibilities I’m aware of in the Kennewick area are listed in post #2 here (and the post it links to).
I have no idea about a mama bear / papa bear approach but it sounds a little silly and to me and only states the obvious (who would actually choose a mattress that they thought was either too firm or too soft for them and softness ratings are subjective and relative to each person). “Word ratings” like “medium firm” have no specific or “defined” meanings. I would take these kind of guidelines with a big grain of salt because each person is unique and has a different physiology, needs, and preferences or what I call PPP (Posture and alignment, Pressure relief, Personal preferences). When you have back issues (or when you don’t if you want to avoid them) then your spine needs to be in its neutral alignment in all your sleeping positions but different mattress designs will do this for different people depending on your body type and sleeping style and many other factors.
I would make sure you have read post #1 here which is the most important post on the forum and has all the basic information, steps, and guidelines you will need to make the best possible choices.
Phoenix