Hi ChristinaM,
Some of the better options I’m aware of in the Parsippany area are listed in post #2 here and some of these are also listed with a more complete description in post #7 here.
There are also some good online options listed in post #12 here if you are comfortable going in an online direction and many of these will also be able to tell you which of their models most closely match the feel of various Tempurpedic models and one has a complete line that is designed to match the feel, the design, and the layering of the Tempurpedic lineup.
Regardless of which direction you may choose … I would always start by talking to and visiting some of your more local options that a phone call indicates make or carry a mattress that may be similar to what you are looking for.
Phoenix