Personally, unless there's something precluding you from doing it, I'd
buy a large 21" CRT and set the resolution to whatever suits.
I dropped my old 21" CRT in favor of a 20.1" LCD. I had (and actually
still have) three of the rather expensive 21" monitors; which I loved
.... until I got the LCD, that is.
The LCD, at 1680x1050 native resolution looks *far* sharper than any of
the 21" monitors ever did, even at resolutions of 2048x1536! And yes,
all three monitors not only supported that resolution, but their
pixel-density was sharp enough to handle that. However, when you add in
screen-effects, tiny misconvergence, slight mis-focus from
corner-to-corner, and similar defects that CRT displays just *cannot*
avoid; yet that digital displays just do not have, the result is a much
sharper image at a lower resolution with an LCD panel. And *modern* LCD
panels don't have the color-depth limitations that early models did.
Side-by-side comparisons of exactly the same picture; and the LCD I have
so far outshines the old CRTs (yes, even incredibly expensive 21"
models) that I'd truly hate to go back.
My only BEEF is that I did (and still do) prefer the 3:4 aspect-ratio of
a CRT to the 16:9 "wide-screen" ratio of the LCD panel. Too few things
(including most especially things like digital photographs and TV
displays) are native in wide-format. HDTV is, of course, *IF* you can
afford the high price of such a TV-tuner. I expect however, over time,
that factor will tend to reverse itself as more people get wide-screen
displays; and wide-format becomes the standard.