Hi Capozzolo,
The first place I would begin your research is post #1 here which has all the information, steps, and guidelines that can help you make the best possible decisions.
As you can see … I would focus much more on the materials in a mattress than on the brand label on the mattress. There are many smaller manufacturers that use the same materials as the mattresses you are considering that may have much better value (neither of the manufacturers you mentioned typically have particularly good value compared to others that use similar materials).
If you are only interested in Simmons Natural Care or Natura then then you can find the nearest retailer for the Simmons Natural Care lineup with their retail locator here or by contacting Natura here.
both of these are high quality mattresses that use high quality materials (mostly latex) but are not particularly good value compared to other mattresses that use either similar or the same materials. A forum search on Naturepedic or on Oganicpedic (you can just click on either of these) will bring up more information about them. They all share the same theme of “good quality but not good value”.
There are not a lot of good options in your immediate area as you can see in post #4 here) and I would tend to focus on the New York area (post #2 here has the better options I’m aware of there and post #7 here has a more categorized list with some more detailed descriptions) or in the Connecticut area (see post #2 and #4 here) or possibly some of the better online latex options where you have much better choices.
Phoenix