I agree with most commentators, you should go with blog, because it's easier to update If you don't like to write you can buy some content at first, but I don't think you will always buy content from someone. I'd suggest to make it public blog, so everyone can post their reviews.
Actually m new with blogs SO i was thinking about an idea to have a webpage with ALL CATEGORIES on it and then all links and list for different reviews(which are in blogg).....I m not sure wether i can keep home page of blogg constant which contains main categories and lists of things being reviewed any idea about that?