Hi lpad007,
I’m not sure if you are looking for a component mattress or you are looking to build your own DIY mattress with separate layers that you design and put together yourself.
If you are looking for a component latex mattress then the mattress shopping tutorial includes a link to a list of the members here that sell mattresses online (in the optional online step) and many of them also make latex and latex hybrid mattresses that use different types and blends of latex that have a range of different designs, options, features, return and exchange policies, and prices.
If you are looking to design and build your own mattress out of separate components and a separate cover that you purchase individually then the first place I would start is by reading option 3 in post #15 here and the posts it links to (and option #1 and #2 as well) so that you have more realistic expectations and that you are comfortable with the learning curve, uncertainty, trial and error, or in some cases the higher costs that may be involved in the DIY process. While it can certainly be a rewarding project … the best approach to a DIY mattress is a “spirit of adventure” where what you learn and the satisfaction that comes from the process itself is more important than any cost savings you may realize (which may or may not happen).
If you are looking for something locally then if you let me know your city or zip code I’d be happy to let you know about the better options or possibilities I’m aware of in your area.
Memory foam is a comfort material not a support material so you won’t find a mattress that uses memory foam in the bottom layers.
Post #2 here and the more detailed posts and information it links to also have more information about safe, natural, organic, “chemical free”, and “green” mattresses and mattress materials that can help you sort through some of the marketing information and terminology that you will encounter in the industry and can help you differentiate between them and answer “how safe is safe enough for me” so you can decide on the types of materials you are most comfortable having in your mattress. These types of issues are complex and are generally specific to each person and their individual sensitivities, circumstances, criteria, and lifestyle choices.
Your budget is probably too low for most all latex mattresses … particularly if you are looking for certified organic latex … but some of the lower budget latex and latex hybrids I’m aware of are listed in posts #3 and #4 here.
Phoenix