I have 300 pages off original content from a writer. I have a pr4 site, would you add these pages internally to your site or write in other peoples blogs with a link back to your site? Which link would be more valuable for link power?
Based on the assumption that this is mediocre copy and you just want to get the most out of how you distribute it - go for external links if you can get them. However if it is mediocre copy you'll probably struggle to get it hosted on any really good blogs.
If we change the assumption and say that all of the copy is high quality, engaging and genuinely interesting then I'd say host it on your site and go out and promote it to other people in order to encourage them to link to it.
Based on what I see ranking these days (lots of stuff with links from articles) I'd suggest considering making the entire 300 articles available to others. Spend the time getting the articles published rather than getting links to them.
There's a lot more people willing to publish articles than there are people willing to link to even high quality articles.