Setup for math, programming, computer literacy tutorials

I want to set up a screen with two camera input:  

One camera is pointed at me.  One camera is pointed down at a pad of paper.  I want to be able to switch cameras with a keystroke.  Each camera needs separate rotate and mirror options.

So far this doesn't seem possible within zoom.

A second way to do it would be to have a camera aimed at either whiteboard or notepad and bring that up on a second monitor at my end, then I can share that screen.  This doesn't work two way, as most kids don't have a dual monitor set up.

I can see it likely meaning that a student needs to acquire a bit of hardware.  Most laptops now have cameras built in.  Many kids have cell phones, and/or their parents have an old phone.  This gives a second camera.  There are inexpensive adapters to put a cell phone on a tripod.   USB cameras aren't very expensive, but tend to be less capable than a phone. 

Need to ensure that there is only a single audio channel present.

It's really hard to have a camera looking over your shoulder and write.    You want the camera support on the opposite side, across from where you sit.  You want the camera for the writing platform  looking straight down so that the whole image is in focus, and you don't have keystone distortion.

Apple phones tend to auto rotate the image, and this gets confused when the phone is horizontal.

In a typical session I may want to:

* sketch on a pad

* write equations on a pad

* lay a sheet of graph paper over the pad

* lay a calculator over the pad, and show how to use it.

* Bring up a program on a second screen (Geojabra, matlab) and show them how to use it.

* have a mini window showing me what I'm currently transmitting.

* have the student run a program on their screen in a way I can see their work.

Anyway, I'm looking for ideas on how to best set this up.