Payment system integration

First, please read complete description, before you place your bid! Description: ----------------------------------- I need an integration of the payment system "DIREKTebanking" (must be this payment system!!!) like the folowing: There are 2 types of registration forms. One form for user group "A" and one form for user group "B". All registered users "A" (only active one), should get specific datas of new reigstered Users B via Email. In this Email should be a automatically generated DIRECTebanking payment Link included included automatically generated payment subject (unique payment number) and payment amount. In one of the registration form fields of the registration form of user "B", it's possible to set the number of users "A" who can pay via the payment link in the Email which user "B" get. If the number of payments (not clicks) has been reached, the DIRECTebanking link should be get automatically nulled/invalid, and all other user "A", who then click on the link in the email, should get an error page, with the text that addition payment are not possible. The users "A" who paid successful via the link in the email, should get specific datas of user "B" via email automatically. ------------------------------ If there are any question, please ask before you place your bid! 50% escrow payment to start. Escrow release and addition 50% after job is done completely.