Hi dstefano,
The better options and possibilities I’m aware of in the San Diego area are listed in post #2 here. There is also a link to a list of some of the better online memory foam manufacturers in the “read first” post #1 here.
Post #2 here has more information about trying to duplicate another mattress. You won’t be able to “match” them by feel because you would need to test two mattresses side by side in real time to know how they compared based on your personal perceptions and memory foam manufacturers wouldn’t use the Sleep Innovations as a target to build an equivalent mattress so that would only leave a comparison based on the quality of the materials (which has nothing to do with how a mattress feels) as a way to compare them.
I’m not so sure you would even want to duplicate the quality of the materials in the Sleep Innovations mattress because it uses low quality 3 lb memory foam in the upper layers which I would normally avoid (see the memory foam guidelines in post #10 here).
Phoenix