All LCD monitors are digital internally. It is the accepted input that may be analog, digital or both.
I would say, that in normal use, there is no visible difference between an analog or a digital ouput from your video card.
Over long distances or through splitters, digital signal will not lose quality, whereas the analog VGA signal may get worse. This is not an issue for you unless you work in a very noisy environment and/or send the video signal over 20ft away.
You should get a display that supports both kinds of input, so you would have some flexibility.