Hi schroedernd,
The first place I would start is post #1 here which is perhaps the most important post on the forum and will give you the basic information and guidelines you need to make the best possible choices.
As you may know … Dreamfoam (which is a brand name of Brooklyn Bedding is an invited manufacturing member of this site which means that I believe they are among the best quality and value in the country. They don’t have a return policy on their Amazon mattresses although they do offer a layer exchange on some of their mattresses and they do have a 10 year warranty on their mattresses.
The better options I’m aware of in the Medford, Or area are listed in post #4 here and these both of these carry latex mattresses that you can test.
Phoenix