Available light shooters tend also to fall into the impromptu/street, rangefinder or press camera mode of shooting. A few come to mind.... Weegee. Winogrand. Kertesz.
A prime recent example would be Ragnar Axelsson, whose understanding of the (challenging) available light of the north is clearly evident in his informal portraits in Faces of the North, which I described here. "Rax" is the man when it comes to available light environmental portraiture, in my opinion. Though you may be looking for more formal compositions.