Help with choosing a helmet?

No motorbike helmets. They are too heavy and provide no ventilation. Go to a snowboard shop and try on all the helmets they have to find the one that is snug but not too tight and is comfortable. Today's technology has progressed enough that the industry can make a light-weight helmet that provides the most protection you will ever need. If you need a full helmet to protect your face (if you think you really need it) look for snowmobile helmets.