Seek alternative to USB-C "Wall wart" for Pi4

I’m building an “Apple Pi” - or more specifically looking to install several Pi4 boards in a Macintosh Classic case. the idea will be to have an internal gigabit; “back lan” use wireless keyboard and mouse and use WiFi for connection to the outside world, and just one IEC “kettle” plug at the back

I don’t want to fill the innards with OEM power packs/ power blocks etc, and to that end have invested in a 5V 10A regulated power supply (and a 12V one for hard disks and display) to use as a “power bus”- the most obvious way to wire this up would be to use the USB-C connection,I don’t want to use the GPIO connection or solder to the board

Is there an adapter I could put flying leads onto the bus and still have access to both the micro-HDMI sockets?