Real Estate Scraper/Integration Data Capture Filter --Joomla

We need someone to integrate multiple websites that have free information about real estate listings into one site, You would need to be able to to scrape sites for readily available kml/xml feeds to integrate into a database of values, these values that are obtained contain the: Name coordinates (longitude,latitude) image href link (icon for home unit etc) Price Description House Image This information needs to be able to be ran on a cron to pull off of the other sites automatically each week or slowly over time to keep current. Past property information needs to be kept on file and available. This needs to be pulled from the websites into our database with a time stamp attached, if the information has changed (eg price, description, availability) then this needs to be added to the site also with a timestamp attached to show the current information and the previous information. You will need to be able to heavily filter on the information both the current and past and past to current on areas (for instance, trends in price drops in areas) It needs to be able to integrate into Joomla! as a component or be built around a Joomla! base. More information will be required, and i can send out more documents if you are interested with site references.