Hi ZuZu,
When you are purchasing a mattress that you can’t test in person then the most reliable source of guidance will always be a more detailed conversation with a knowledgeable and experienced online retailer or manufacturer who will know more about their own mattresses than anyone else and are in the best position to help “talk you through” the options they have available that would have the best chance of success based on the information you provide them along with the “averages” of other customers that are similar to you (see mattress firmness/comfort levels in post #2 here).
There is also more about the different ways to choose a mattress and how to lower the risks involved with each of them in post #2 here but the best starting point for an online component mattress would generally be the suggestions that they provide and then if your sleeping experience indicates that it’s necessary you can further customize the mattress either by rearranging the layers or by exchanging a layer for a firmer or softer option based on your actual experience.
SleepEZ also doesn’t normally offer 14/15 ILD latex option (they can special order it but they won’t warranty it) because of the additional risks involved for most people both in terms of durability and in terms of the alignment risk with a latex layer (or any material) this soft. Of course you can always purchase a topper in this ILD range if you decide that you would like to try it but it would be a more risky choice than latex layers that are a little firmer (but still in a soft range).
Phoenix