The topic of "what sights should I buy" comes up a lot on firearm message boards & forums.
I'd look at the Warren, XS, Novak tritium, & Trijicon HD night sights(green & orange).
These systems are highly rated & in use by armed professionals/concealed carry license holders.
I'd say the Trijicon HD sights could be the best choice, but your tastes/budget may be different.
See; www.novaksights.com www.trijicon.com www.glockbooks.com www.customizeyourglock.com www.bowietacticalconcepts.com www.brownells.com www.glockstore.com