Big cogging is not good for gimbal, because main principle of this kind of stabilization - use inertia of a camera while mechanically unbind camera from the main frame. Cogging will tie camera to frame.
So, you should choose motors with minimal cogging effect. If you able to turn motor holding its shaft by fingers and not applying to much force, cogging is good.
Schematics pretty simple but it will not work without firmare. Unfortunatelly firmware is not open source and will not work outside "oficcial" boards from my partners.