I'd look at the top rated Trijicon HD 3 dot system;
www.trijicon.com .
I like the orange-green styles. They should be available for the Beretta M9/92FS series. The armed forces & D0D signed new contracts to carry Beretta pistols until 2016/2018 or so. After market parts & sights should be around for many years.
I'd look into a Crimsontrace lasergrip too. They are easy to carry-set up & you can use them for skill training or to aid marksmanship.
Crimsontrace offers a new 2013 free DVD to explain the product line & display lasergrip/laser-aiming tactics. See:
www.crimsontrace.com .
I owned a slick Taurus Protector snub CT lasergrip in the early 2000s.
New green lasers may be available later in 2013 or early 2014.
Clyde