Comment on Cloak Affiliate Links Tutorial by SEO Dave.
Beyond the above Stallion doesn’t track clicks etc… I’d look for a WordPress tracking links plugin. I doubt you’ll find a plugin that tracks conversions on the site you link to though, that’s down to the site owner to track and provide the info.
What you are basically looking for is an affiliate program like Clickbank or Amazon where their system tracks everything so you and they know the information is accurate. Not really what you are looking for though.