Daisy-chaining or y-cord audio and power trigger connections?
If you are using Bus #1, daisy chaining audio is easy as there are two sets of jacks, one of which can be used to drive the next amplifier. Also the impedances internal to The Director on the other RCA jacks allow for using audio Y-cords.
For power control, the easiest is to have an Ethernet connection to each unit. The 12 volt mini jacks are powered to turn on another unit when the main unit is on (not standby). If you need more than 15 milliamps current on the 12 volt output, use a relay to prevent over loading The Director. (The Director itself only takes 1 milliamp to turn on.)