Search Bot and Parse

I am a auto dealer looking to purchase cars online and would like to write and app or bot that will search the major car sources: Craigslist, ebay, cars.com. The tool will have to have all the standard search queries Make, Model, Year, Price, Location, distance from location etcs. but also aggregate the results in a database format that I can scan and quickly.. For example Search all sites for a Porsche C4S I would get a list 2000 Porsche Carerra C4 phoenix $60,000 email address phone number 2001 porsche carerra C4 phoenix$62,000 email address phone number I than can click on the summary line of each car to get more detail.. Once this has been sorted I would than like to use the list to send either individual or bulk emails For example send an automated response to all checked cars and say " I am interested in your automobile is it still available and what is your best price.." And than if possible I would want the software to update the list if emails come in, parse the email and and the new price and if it is available on the summary sheet. My goal is to ultimately automate the buying process for cars nationwide from individuals and eliminate as many of the people that are not willing to sell or negotiate.