I will assume this is for a home.
Amigos de Bucerias has a referals list on the website and you could also post on the Bucerias Yahoo Group which will get you local information and recommendations on who people have used and been satisfied with the work performed and cost element etc.
Just about any Aluminio y Vidrio place ...... but it depends on if it's just the glass or the whole window. Wood, steel or aluminum? Lots of them here in Melaque but I doubt they would travel that far north