This 90A Current sensor is designed for the Pixhawk II and plugs in directly without the need to change connectors. If you're using an older Pixhawk 2.4.x style system, they normally include a cable that will plug directly in to this, or you can easily make extra cables using this kit!
The Power Module is only designed to power flight controller, an RC receiver, and flight controller accessories (GPS, airspeed sensor, etc..). It is not designed to power servos. Use your aircraft's own ESC/BEC for that.