You could try out
Mambo,
XOOPS, PHPNuke/PostNuke or some similar CMS. I also need to find one for a new article site I am going to work on. I have used all 3 systems in the past, and switched between them a few times. Take a look at the list of features and go from there. As far as the layout is concerned, with Mambo, you can choose if you want a two column layout, or a leading story, then the rest of the articles will be below it. There are always hacks you can download and try out. It also has an article rating system, and a forum addon.