web crawler and scrapper

I want you to help us present the data from number of websites. We need a comparison table from different websites that are dealing in similar products. The website should reroute to the website where data is originally taken from upon click at this stage. It must not take much of your time to crawl and scrap the data if you are using a script. The important thing about the website is that it should be easy to mange and handle from multiple sources. There must be an easy way to accommodate more comparison websites in current project. Both admin and client end should be available so that client can rate the products and admin can add or ban any user. More details can be provided.