4:3 vs 5:4 LCD

I am thinking of getting a 17" to 19" LCD monitor and want to edit home movies and watch TV at times (time shifting). All the TV and camcorder video that I have is in 4:3 format. Does anyone know what will happen if I use the 5:4 format 17" panels to watch 4:3 video sources and edit them? Will I get black borders on the top and bottom of the screen, or will the picture be stretched and distorted to fit the whole screen?

As far as I can tell, the LCD monitors have the following ratios:
15" - 1024x768 = 4:3 (too small)
17" to 19" - 1280x1024 = 5:4
20+" - 1600x1200 = 4:3 (too expensive)

If the video card makes a difference, I have an ATI All-in-Wonder Radeon (an oldie), but I can upgrade if needed. Any advice would be appreciated before I spend the $$ and end up unhappy.