Recommendations on clone of odesk/freelancer?

Hi - could someone please recommend a freelancer or odesk clone? I won't be doing the same thing; i'm doing a niche that requires the same user interface.
I'm trying to avoid spending so much, this being a test site and trying out traction.
All ideas/suggestions warmly welcome - thank you.

Use a framework like Yii, or Zend. Don't build it on Wordpress or you will end up messing up everything when your project becomes a hit. A good db structure is a must!