See picture above the middle 2 switches, I would like to replace with z wave. There are a 1 way switch.
You were asking about two paddles in a single gang switch space.
The short answer is that there used to be, from Leviton, but that device was discontinued in 2016 and they have not said one way or the other whether they are going to put out a new Z wave plus version of it.
There are a number of threads about this in the community already. There are some alternatives depending on your exact set up. See the following ( this is a clickable link)