Power to CB first.
Otherwise there is no circuit protection for the wiring to the E-stop.
Also, this allows you to turn off the CB and all of the wiring in your panel should be dead.
One thing I have done since the internet age... is google
When making drawings and designing a system I like looking at others and taking their ideas, I use to go threw a bunch of old drawings from Germany, they had good ones
Here are a couple I found on Google and they did it jawolthuis's way, (I also do it that way)