Facebook Social Connect Implementation In WordPress Site

Hi There, Im looking for someone to implement Facebook Social Connect into my website. i.e. Allowing user to register with Facebook with one click of a button. The site currently has it installed but i dont think its working correctly. A lot of spam users are signing up, im not too sure whether this is being done via the current facebook connect option or the standard registration. Advice on this is required. The site is a little slow too, so ideally i would like some suggestions with a cache plugin too to improve site performance.