[sfmz]

You didn't specify budget. I think laptop form-factor is impossible to beat ergonomically, so color e-ink laptop -- then you can turn the page with the spacebar.

eg, Lenovo ThinkBook Plus Twist HANDS ON: Color E-Ink and OLED in one Laptop

https://www.youtube.com/watch?v=toRHQhR4UPI

[racyred44]

It's too big to fit in a small messenger bag. Edit: and looks ugly as well.

[sfmz]

Buy a bigger bag; it looks like a laptop, because it is a laptop.

[racyred44]

If it looked like an IBM ThinkPad I would have bought it.