The WMR-968 console will not work with your WMR200. They use different sensor protocols on transmit of their data.
If you can purchase an additional wmr200 console, then I don't see why it should not work.
After all basically the console is a radio receiver.
On my WMR968 based station, I have 2 OS-wmr968 consoles, and 2 other Radio Shack consoles, that use the same sensor protocol. So in total 4 "radio receivers" for my sensors. All Works Great.