Anything under 500cc will be about the same insurance premium, so why limit yourself to 50ccs? The Big Ruckus would be great but hard to find and more expensive. The Vespa will have more lower fairing coverage. Consider the Honda Grom as well. Why are you going smaller, rather than sideways/a little larger?
My recollection of a 70cc Honda Passport, 3sp was not good for keeping up with traffic, and suspension was bone jarring. Ditto for a friend's Tomos 50cc moped, who incidentally pays $400/yr to insure. Skinny tires, limited suspension = bone jarring, close to having your fillings vibrated loose.