That's exactly what we use at work. A laptop with an external screen.
1. We have 23" or 24" with a normal HD resolution (1920x1280). Works fine for me. You'll have to try what suits you.
2. Most monitors are matte (like most LCD/LED TV's).
3. It's nice to use an external keyboard also, so you can move the laptop out of the way. And you might like that the screen is on the same height as your eyes.
I have a 15.6" laptop with win 8.1 and working fine. My work involves reading/editing word documents, working excel and some programming. I have developed eye problem and causes pain while reading small letters. I have to zoom screen 110% that results in little space on laptop for working. I need some advice in buying external monitor to connect with laptop.
1) Which external monitor size will be best for work?
2) Is matte screen in monitor enough for eye protection?
3) What are pros and cons of connecting external monitor to laptop?
Looking forward your reply. Thank you.