Need a Programmer with Raspberry Pi / Linux experience to customise a Linux image

I need a Programmer who is very experienced with Linux / Raspberry Pi to take an image I have ripped from a device, and customise it according to my preferences.

At present this image is simply used to operate a Hi-Fi stereo system, and the HDMI port is used as Audio Out only, the sound is internally routed through the stereo's internals and through internal amplification comes out via attached passive speakers.

I would like to have 3 operating systems on the storage.

I would like

1) The current distro/OS
2) OSMC
3) LineageOS KonstaKang

And I want to be able to switch between these operating systems with certain key combinations on the current remote control.

So default OS would be 1)

Then, for example, If I pressed button 1 + 2 + Menu it would load 2)

Or if I held down 2+4+menu, it would load 3)

For example.

I need the sound to continue working, but the HDMI port to function as a normal HDMI (video+audio) for both OSs 2 & 3.