Integrating external check in Oscommerce

We are looking for an Oscommerce expert to integrate a check module on our site. The purpose of this module: When a customer is at checkout_shipping there should be an internal check if we need the financial details for this customer. If the details need to be checked, there will need to be a check(XML) send to an external company to verify the details of the address provided and if we can ship the items in advance with an invoice OR that the customer has to pay in advance. If the check is not correct, the customer should be redirected to a payment in advance page. (cash in advance, PayPal etc) If the check is correct, the customer can go to the standard checkout_payment page. To be created for this project: Catalog side - Check after checkout_shipping based on details in Admin - Waiting page (we are processing your details, one moment please) - New chekout_payment page with only cash in advance payments Admin side: - New Box (financial check) - How many details to be checked (up to 9 possible) - When goto payment in advance (of this 9 choices, or combination) - Time untill time-out (you can't have customers waiting all day) - When Time-out goto (checkout_payment or payment in advance) - The server address for the creditcheck company - Number of request made with external company (for invoice check) Due to bad previous experiences we will pay for the project in full when it is finished, we will not make a downpayment. If this is a problem for you, then please don´t bid on this project. We are only looking for oscommerce experts who know the ins and outs of this program. Delivery should take place as a contribution so including the files to amend, since we want to donate this contribution to the oscommerce community after completion.