Hi ron bruce,
Hopefully the layers you choose will work well for you but they won’t be similar to the Tuft & Needle mattress because they don’t use HR polyfoam in their mattress. You can read a little more about the high performance foam they use in their comfort layer in posts #2 and #6 here.
You won’t be able to duplicate the Tuft & Needle anyway because you wouldn’t be able to purchase the foams they use in their mattress but all that will really matter is whether the combination of layers you purchase is a good match for you in terms of PPP regardless of how it compares to Tuft & Needle.
Good luck in your DIY efforts and I’m looking forward to finding out how your design works out for you.
Phoenix