Hi Dobermakduke,
There is more about hotel mattresses in post #3 here.
The Doubletree hotel mattress is made by Serta but they aren’t sold in retail stores and the only way to find an “equivalent” would be based on your own personal testing on Serta mattresses that use their continuous coil innerspring (the Perfect Sleeper line) in a store to find one that “feels” the same to you.
I would avoid them along with any of the major brands or any mattress that uses lower quality or “unknown” quality foams in the comfort layers (see the guidelines here). There are much higher quality and better value mattresses available and hotel mattresses are a common source of buyers remorse much too quickly after a purchase.
The better options or possibilities I’m aware of in your area (subject to the guidelines here) are listed in post #8 here.
Phoenix