Ok, time to dispel the screen readability psychosomatically enforced myth hehe.
I am currently using a 17" monitor (16" viewable). It is running at 1920x1440, 68Hz. (monitor can't handle 70Hz with this resolution unless I make the front porch/back porch timings too small and get ugly edge effects).
I have absolutely no trouble reading it at that resolution. The clarity is not perfect, but that is due to the monitor dot pitch, not the text size. In fact, if the monitor was of higher quality, 16" viewable would be perfectly fine for reading standard fonts at 5000x5000 resolution.
A few facts:
1) Most programs default to 12 point fonts.
2) Newspapers standard print is 10 point.
3) On a 19" monitor, the text is almost exactly the same size it will be printed if you are at 1600x1200. (at 100% zoom in word or other programs)
There is some psychological effect going on that people see on-screen print as smaller than on-paper when they are the same. Probably from looking at the blurryness of old monitors before 0.25-0.28mm dot pitch became the standard or from the crappy quality of TV screens (most of which have a dot pitch above 1mm).
With an 18" viewable area (about like a 19" monitor), in order to display 1600x1200 resolution with no pixels being blurred together, you need 0.228mm or better dot pitch. Chances are (unless its really top notch), the monitor is probably closer to 0.26mm dot pitch, so there will be a bit of blurring, but not too bad.