I found that what really matters for great-quality reading off the screeen is pixel per inch, not the raw amount of pixels.
I have no idea why but if you want the maximum resolution on a stand-alone monitor, you need to get a huge one. which defeats the point since I don't want to do much saccadic movements while reading -i.e., the smaller size the better-.
I currently use a laptop with a UXVGA screen -I think- (1920 x 1200). I place the laptop vertically (i.g., portrait, not landscape).
I have written about reading off the screen here:
Adobe Acrobat as a solution for reading articles off the screen
Reading PDFs off the screen? Advantages
This gets me what I want, a UXVGA screen on a small form factor: best pixel per inch ratio. And it's portable to boot!
They say laptop monitors are not high quality, but I have no qualms with mine.