I usually use a boning knife or big German chef's knife to deal with chicken bones. The German knife is just about burly enough to cut through the neck, if I'm getting chickens that have the head on. The standard technique is to place the back of the blade on the neck, between two vertebrae, and give it a thwop with your other hand.
I once made the mistake of trying to cut through a turkey neck with the chef's knife; that sent it to the repair shop. Now I have I have a $10 Chinese cleaver for the times I need to go through something a little bigger than chicken bones.
Basically ...
Japanese gyuto: no bones
Western chef or boning knife: up to and including fish heads and chicken necks
Cheap heavy cleaver: turkey necks
Hacksaw: anything bigger
Edited to add: the chef and boning knives work fine for slicing through the rib cage when fabricating chickens. Just make sure to separate the joints when you get to the bottom, rather than trying to cut through the pelvis (I assume that's what that is).
