QUOTE(xboxgamer733 @ Feb 18 2007, 10:44 AM)

Before your described setup will work, a VGA BIOS would have to be flashed to your Xbox (you can also use a VGA-enabled NKpatcher softmod). Because of this, your Xbox could not remain unmodded. After this is accomplished, your setup will work fine if your monitor also supports 'sync-on-green'.
However, if your Xbox is unmodded, and you would prefer to keep it that way, you would have to purchase a device like the X2VGA+ to allow your Xbox to output a VGA signal.
The X2VGA+ won't make your Xbox output a RGB (VGA) signal, it will take a component signal and convert it to RGB. The only way to get a true VGA signal from your Xbox is to do what you suggested in your first paragraph.