Custom Wordpress Classifieds as Wordpress Plugin

New classifieds for wordpress. able to perform like [login to view URL], [login to view URL] requirement : 1. use a separate database than wordpress' default, must be mysql 2. login and username must be able to integrate with the new classifieds for plugin 3. plugin must be modular and totally independent of wordpress framework other than using global information such as global $current or global $bp; (buddypress) 4. must perform like [login to view URL] or [login to view URL] 5. must NOT use existing classifieds plugin 6. MUST NOT BE theme. private msg with how you'll go about doing it.