News feed fed by multiple sources plus commenting function

My website [login to view URL] is growing and about to get a big fundament of content. What I basically want to do to the html based website is enable users to comment and rate each of the articles, as well as implement a news feed, which is fed by multiple financial sources. Also on the home page there should be a little column, presenting small news stories from the feed. I would like you to make any suggestions on how that could be achieved in a manner, so that adding further content and maybe updating the design could be done without much of a hassle. Looking forward to your offers. Best regards, Luca