Re: WS monitors and gaming
The LCD monitor will display the old-school 4:3 resolution either by stretching it to fill the screen; filling vertically, leaving black bars on the sides; or doing pixel-for-pixel mapping, leaving black all around. There is usually a setting -- commonly buried in a menu -- to switch between these three modes. Some monitors might do only two of those. The third one is probably not suitable for gaming. (For me, neither is the first.)
If your desktop resolution matches the native resolution of the monitor, then either setting will have the same effect on the desktop; i.e. it will fill the screen, no distortion. Then when you play the game, it will do whichever you prefer.
Then the only other thing you need to check is whether your video card supports the native widescreen resolution of the monitor. They're 16:10. 24" range is 1920x1200; 20" is 1680x1050.