The latest complete quirk list is in Campaign Operations (2nd printing/revised). Otherwise, the BMM.
It depends on the nature of the quirk. In some cases the fluff makes it clear the bonus is due to the weapon mount, in others because it's an accurate weapon, and still others because it's the targeting system. AA in particular is a targeting system, as are any of the variable-range targeting quirks. Stabilized weapon could work fine, however. Beyond that, this is a GM/group call, rather than a hard and fast set of rules.