Customize existing website script.

Want to add some features customization that are present in WhizBiz - Business Directory CMS in another script i.e. Whiz Classified - Classifieds CMS available at codecanyon market [login to view URL] Script are similar alike need an expert who will modify the Whiz Classified . Requirement details with screenshots are provided after seeing some sample [login to view URL] founded some bugs in Whiz Classified script so in customized version want to resolve [login to view URL] want to integrate Rental Booking option (Mentioned in requirement doc) i.e a Book now button & widget with availability calendar option .1st i want to add/modify those features in Whiz Classified script which are already featured in Whiz biz [login to view URL] finalization we will discuss further.