Advanced Search For Ads

Hi, I would like an advanced search block to work with the ads section of my site. The site will be an advertising site so that users can list properties, cars, items etc for sale. I am able to use the ads module but i need a better search facility so that the users are easily able to search for exactly what they are looking for within the ads.

ie, users go to site and finds the search on the index page then chooses from a drop down menu the category (say they choose a house) then they choose the location and then the bedrooms, price etc. But also, if they choose car, then there have to be options for cars etc.

Thanks

M