I ordered a yongnuo kit recently but haven't gotten the part yet. From my research I can tell that the RZ67 has both a regular hot shoe and an x sync output, so the transmitter will most likely work for you. Likewise the 285hv should work fine, as it can be triggered through its center pin on its hot shoe and has a low trigger voltage.
So I'd say yes it will work fine, but that's solely based on theory, I'm still waiting for the parcel to arrive.
One more thing: the yongnuos boast a min sync time of 1/250, but this will only hold if you use it together with a system camera (Canon, Nikon). If you use it with your RZ67, the sync time will be slower, I've read numbers about 1/160 or so. Only the system cameras send a "something is about to happen" signal through their hot shoe which puts the yongnuo into (high current draw) alert mode, in which it fires faster. So sorry, no 1/400