Affiliate tracking in Wordpress

Hi, I need someone to help me to track affiliates, on existing Wordpress blog. Affiliates will get banners and they will get link for example : [login to view URL] Freelancer provider must know : 1) php,javacript and Wordpress 2) To know websites for tracking or Wordpress plugins for affiliates. I plan to create some affiliate competitions too and I will need freelancer provider to be in that process, create affiliate links and his important role will be : protection from fake clicks. This cooperation may be longterm so I will ask several question to check provider experience. Maby I will pick several providers for this job.