I'm thinking about switching from 3rd party flashes to Canons. I photograph weddings with 2 bodies. One has a flash, and the other doesn't. Both have triggers to two flashes on light stands. I was thinking about this setup: Body 1: 600EX-RTii Body 2: ST-E3-RT Lightstands: 430-EXiii RT. Am I correct in assuming that the 600 will trigger the 430 via built-in radio? Also, it looks like the ST-E3-RT costs nearly as much as a 430 flash. Could I use the 600 as one Master on one body, a 430 as the Master on the second body, and then the other two 430s as slaves on the stands?