Help needed - Paypal Mass Pay API and IPN

Hi. I am seeking help/guidance with PayPal Mass Pay API and IPN configuration with our current project. The purpose of Mass Pay API is to make mass payments upto 250 affilates in one go automatically via our current application (build in PHP +MySql + JavaScript). The purpose of configuring IPN is to update affilates account with transaction number + Amount Paid once the mass payment transaction has been processed. This transaction will be done once every month to send payments. Our client has a PayPal business account. Please bid only if you have used the Mass Pay API and IPN before and able to show sample work. Payment will be released ONLY after successful SandBox Testing. I have a PHP developer who needs the assistance. Service provider will be choosen as per the low bid and high experience. Thanks, Bipul