What are you using the gun for? Night sights are not necessary for a target shooter working in good light.
If you're not going to be shooting in low or failing light, I would suggest a set of plain steel Novak sights. You can get a plain black front and rear for about $60.
If you will be using the gun for personal defense, then the world of sights opens up to a lot of other options. Sticking with Novak's you have options from fiber optics, to tritium inserts, and the old school brass bead front sight.
Other quality night sight manufacturers include Trijicon and Meprolight. There are also combo tritium and fiber optic sights like those from TRUGLO, and other variations like the XS Big Dot sights.
Your local gunshop should have someone on staff that can install any of these options for you.
XS BIG DOT