Though a pair of pano-cameras can be used to shoot 3D panoramics, a single camera setup is often more desirable considering the ease of handling. One of the noteworthy models is made by Manfred Graumann. The details of the camera can be found here .
To know more about early models of stereo panorama cameras have a look at the book "Stereoscopic Photography" By Arthur W. Judge. A limited preview version of it is available here.