Hi monicam,
Welcome to the Mattress Forum! 
The members of The Mattress Underground are listed in the top heading here. Being a site member means that I think very highly of them and that I believe that they compete well with the best in the industry in terms of their quality, value, service, knowledge, and transparency. They are all extremely knowledgeable about different mattress configurations, and I would not hesitate to recommend any them for your consideration.
The San Diego list here might have some other sources of latex that you haven’t yet visited.
Phoenix