Content Management Project

I am wanting a content management site, driven by say Drupal for a social/lifestyle website that will have approx 7 -10 main categories (food and drink, style, travel, music etc) and be able to display results by different geographical regions based on the categories mentioned above, and all regions combined. There would be multiple data-feeds from different persons that would be loaded up via a control panel to a staging area, with an editor having the ability to update the information before pushing it out in to production. The site's backend needs to be well conceptualized and organized as it needs to be highly scaleable. The frontend should look very trendy, sleek, and user-friendly and will incorporate UI rich internet apps like JQuery, Flash, Video etc. I need to know how long it will take to build and how much it will cost. Thanks Kurt