If you're running 64-bit, I don't think it's possible at the present time. Reason is now 64-bit ReWire compatible, but I don't think either Live or Sonar are.
You would need to run both Live and Sonar in 32-bit mode.
Or, just use the Matrix view to do something similar to what Live does. People complain about the Matrix view, but when used in conjunction with the rest of the program, it works well.