For a control box, the simplest way is to use a switched, EMI filtered and fused IEC connector
www.amazon.com.au/uxcell%C2%AE-IEC320-Sw...Filter/dp/B01FT0VRTS
You can see one of these used at the bottom right of my photo shared earlier.
But in your case, this won't work if you want to switch the router on and off because the current of the router will be too high for the typically 6 amp AC rating. Plus you would not want the electrically noisy router to be on the same side of the EMI filter as your electronics.
So in your case, I would use a fixed power lead and a cable gland to bring mains into the control box to two household breakers around 10 amp. One of these will protect your router circuit and the other your electronics, On the electronics circuit, immediately after the breaker, fit an EMI filter
www.jaycar.com.au/240v-ac-emi-filter/p/MS4001
Then connect all of your power supplies to the filtered mains power.
Filtering the power is really important to avoid spurious triggering from electrical noise. I learnt the hard way.
The next thing to work out is your estop. That's a bit tricky because you need to disable the router and the stepper motor power supply without using any relays that could fail. The estop needs to drop power to your router power and stepper mains motion. You could use 2 phases of a 3 phase breaker but technically you would then need to use a safety relay to be compliant.
Its probably acceptable to disable your stepper drivers using the enable pins on them that are usually left disconnected.
