What do you exactly mean by 'individual transaction fees' ? I can't also understand the kind of API you are looking for and how you across blockexplorer.com while searching for it .
Most of the exemples mentioned by moccacino doesn't offer an api based on a specific need, but you may be can contact them closely and ask for what you exactly want .
You have to explain for what use you want an/this API in simple words so we can help you .