Hi Brenda,
Your best source of guidance is always with a more detailed phone conversation with the manufacturer themselves (in this case SleepEz) who is in the best position to give you the best possible guidance about the initial layer choices that would have the highest odds of success for your body type and sleeping positions. You will find they are easy to talk with and are patient, have a “no pressure” approach, are knowledgeable about any questions you may have about their mattresses, and they will know more about “matching” their mattresses to different types of people and preferences than anyone else … including me … because they do this many times every day (see mattress firmness/comfort levels in post #2 here).
As you probably know I think very highly of SleepEz and you are certainly looking in a great direction 
Phoenix