Changing Lighting and Camera via UI

So I am trying to make a configurator where you can change the camera and lighting via a dropdown menu. I have the HUD setup and working, as I can switch between the objects via dropdown. What I can’t seem to get working is the camera selection or how to change lights via a dropdown.

I can change the camera using a keyboard button, but I’d like to use a dropdown for this.

I haven’t set it up yet, but I would also like to be able to change my lighting setup in a similar way. Dropdown menu that wil switch between either 2 hdris, or 1 hdri and a lighting setup with a couple of rectangle lights.

Any help would be very helpful!