Content Writers for authority sites?

I'm currently trying to setup an authority website with a friend in a small, but growing niche. We both have full time jobs, however are both interested in progressing with this site due to having a shared interest in it.

One of the things we're looking into is content writers, to write pieces such as guides or news stories, taking content from various sources and rehashing it into our own, fully unique content.

Is this something many do, or for an authority site, it is not recommended?
I want this content to be unique and targeted for our website, which does require knowledge in the area.

The last thing I want to do is to hurt future rankings because the content doesn't add value.

I can tell you this, if you know two languages, check other sites in your native language within the same niche, translate their content and add twists here and there.

But for authority site I am sure you need quality content, posted on a regular basis.

Getting a good one through oDesk should be no problem. Set your budget, Add Creative writing and SEO writing as skills, get a native speaker, have a chat about it through Skype and discuss your needs. Many to choose from