That's a great idea.  I've been adding and subtracting fish for about a year now.  I thought about the neons but they would get eaten by the african cichlids and they costa about 3 dollars each here.  I recently put some iridescent blue and yellow cichlids in and they look pretty cool.  I wanted some peacock bass, but that would be the end of the fish population in about a week.  I starting to get a feel for the amount of large fish that a lake can handle.  Man they eat alot.  The larger silver ones that are in there I though would be nice to see waves of silver while swimming but it didn't quite work out that way.  I still might try something neon.