Hi izzyq,
Welcome to the Mattress Forum!.
As you probably know SleepEZ is one of the members here which means I think highly of them and I believe they compete well with the best in the industry in terms of their quality, value, knowledge, transparency, and service. You are certainly looking at a great quality/value choice.
The choice between different types and blends of latex would be a preference and budget choice rather than a “better/worse” choice so it would really depend on which type of latex you tend to prefer. There is more about the different types and blends of latex in post #6 here and there is also more about how Dunlop compares to Talalay in post #7 here that may be helpful in choosing between them although the most reliable way to decide which type of latex you tend to prefer would be based on your own personal experience.
If you are still undecided about your layering and when you can’t test a specific combination in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart (such as SleepEZ) who can help “talk you through” the specifics of their mattresses and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked that they are familiar with, any special considerations you may have, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs or firmness options to different body types, sleeping positions, and preferences or even to other mattresses that they are familiar with than anyone else.
I would also talk to them on a phone call rather than using email (see post #2 here).
Phoenix