My layout (no cabinet yet) is very messy, but here's an old photo of it:
www.delorie.com/photos/cnc2/PXL_20240324_210728573.html
I went with DIN rails for mine, one for mains power control (top) and one for low voltage (middle). The mains rail has circuit breakers and contactors, and the contactors are wired into the estop chain. The main logic power's contactor is wired into the on/off buttons so it defaults to off after a power failure.
You can mount power supplies on their sides if you need to save space.
Don't forget to leave space inside the box for vents and fans top and bottom.
Your estop should be more conveniently located. Or buy more than one of them