GeoClassifieds Facebook Login

Our site is build on Geodesic Solution's, GeoClassifieds 5.2.1, and we'd like an addon to integrate a facebook login system, so our users can use their facebook account to log in. We'd like new users to be able to sign up with their facebook account, and existing users to sync their accounts with their facebook account. We are also using the GeoClassified's vBulletin Bridge Addon, which links our Geoclassifieds login to our vBulletin 4.1.2 login, making just one login system. -We will need this addon to work with our bridge, and keep our users logged in, if they are logged into facebook, on both our GeoClassifieds, and vBulletin Forum. - We need this to be an addon, and work when and if GeoClassifieds releases future 5.x updates. Thank you.