Use Nissin Flash to Radio Sync Slave Flash?

[GGEPhotography]

Hi. I wasn't sure if this has been discussed. I'm looking to use a multiple speedlight set up for event photography. A Nissin di622 mark II on camera and I want to use my yn rf603's to wirelessly trigger one or two other speedlights positioned around the room. I use a d7000 which has no pc sync port and don't like the idea of having to use a hotshoe converter on top of my camera plus the rf603 just to keep the ttl to my Nissin. My question is, do the pc ports/cables work 2-way? Can I have my Nissin directly on my cameras hotshoe and use a cable from the nissin's sync port to the rf603 to wirelessly trigger another flash? I don't want to use infrared or optical slave modes if I can avoid it.