Radio triggers and master speedlights

I currently have a 430EXII and 2 Yongnuo 622c triggers.

I'm planning on adding a 580EXII or 600EX-RT.

Can I use the 580/600 off camera with a trigger, and then use the 580/600 as a master to trigger the 430 (without a 622c)? Or would I need a 622c on each speedlight (I may get more triggers anyway, but I'm curious)?

The 622C on the camera is the "Master", and there can be only one. So for most requirements, you cannot do what you suggest.

There is one configuration that might work for you in a limited way - what Zack Arias calls "Free Agent". You can find that setup in TOYUG - see link in my signature.

Thanks, I'll have a look.