The Clear-Com PL intercom is often called on to connect with a television camera.
All Broadcast Quality high end SD and HD cameras and some industrial versions will have 4 wire balanced I/O connections.  Without exception, this is always the best choice. You will need the Clear-Com IF4W4 interface,  It will allow up to four cameras to connect with superior audio and levels to and from the camera circuits.
Some cameras will offer 2 wire along with 2 wire Clear-Com and RTS modes.   If you are connecting one camera, you can select the Clear-Com option and - probabaly get acceptable level to and from the camera. However, since the camera circuit is bridging the Clear-Com at or near 600 ohms, the moment you add the second camera, (300 ohms) the level will not be ideal for most productions needs.
In summary -- If 4 wire is offered, use it.