Will response rate make a difference? What is good brightness? What is a good contrast ratio?

Definitely there are other things to look for, so please give me your opinion.

Also, what screen size is good for reading? What size would you choose from 17-22? I'm thinking of getting one 17-19 for reading, and one 22 for movies. Or maybe 2 22" one vertical and one horizontal is better?

I think I should look for lower native res., right?