Convertir una plantilla de una web

Hi, I just bought this theme [login to view URL] and I need to adapt it to my specific needs: 1 .- Customize the "search engine" plugin so I can add or delete as many types of "what" as i like (right now it doesn't have any kind of administration that allows that). 2.- Add a regular search box in that same plugin so i can look for a specific item. (Ex."rent a mercedes in barcelona") That's pretty much it, for now... Thanks!!