Let's say I set up a section of my website that aggregated content from major news outlets and bloggers around a certain topic. For each piece of aggregated content, is there a bad, fair, and good range of word count that should be stipulated?

I'm asking this because I've been mulling it over—both SEO (duplicate content) issues and copyright issues—to determine what is considered best practice. Any ideas about what is considered best practice in this situation? Also, are there any other issues to consider that I didn't mention?