Until I moved to the cinema display, I used Viewsonic LCD panels, up to 22", though they make them larger. They are user friendly and generally very good quality. CNET describes some of the Viewsonics and compares them, and though that site is well known for the less-than-helpful bell curve of review rankings, the details are helpful.
When you start up the Macbook, close the lid. The external display should fire up. If not, let it boot normally, THEN close the lid, and the laptop will sleep. Wake it up with a mouse or keyboard input (USB external devices work) and the external display will activate. It took me awhile to sort that out. Once set up, if you keep the lid closed and shut down and reboot normally, the external should remain active. Of course, tat's hard to do without an external power button, which the Cinema Display provides. But anyway. Otherwise, you can always have both screens going and mirror them, or extend the desktop across them.
