New WooCommerce Payment Gateway

I need a new payment gateway for wooCommerce. This are the requirements : - At the checkout the user has to fill 3 new text-fields --- Name --- BIC --- IBAN - This fields must be stored at the database - After this the checkout is done, but the order/invoice is still unpaid - The admin must a have a new menu-item at the backend, where he get's a list of all unpaid orders/invoices with this payment gateway - At this list we need the fields : --- order/invoice number --- order/invoice date --- order/invoice amount --- Name --- BIC --- IBAN - If the admin hit's a "start processing" button at this new backend-page a batch-process will start and do : --- creates an email that will be sended to the order/invoice customer - i will define the text --- mark the order/invoice as payed --- creates a new record with this fields ----- date (now) ----- number of assigned records ----- amount of all assigned records Code must be well documented Code must be multi-language ready ( with he default wordpress functions __ and _e ) Code must be multi-site ready Code must be multi-currency ready