A good fairing system starts with a bike that fits the rider comfortably. The lower the shoulders, the less frontal area you have. The fairing guides the air around you smoothly. Just a front fairing doesn't do that well enough. My big touring style winter fairing is 1 mph slower in a coast down test (16 mph) without a matching tail box. ALWAYS mount the fairing to the frame, NOT the handlebars. That way the wind will hardly affect steering.
For safety use a rear view mirror and lights. Check the local auto parts store for light weight dual racing mirrors.