If you DO have to replace the sights I the think Trijicon 'long rear' are best of breed for S&W 3rd Generation pistols. They are a direct replacement for the Novaks, tend to be cheaper than the Novaks and offer a better sight picture. However, they are a real tight fit (no set screw like the Novaks have) so getting them on/off and adjusted requires a sight tool with lots of 'oomph'.

All of my 'social' 3rd Gen pistols either currently sport Trijicons or will in the very near future.