Chase Paymentech Integration to custom checkout

This project is for adding credit card acceptance into a custom site. Presently the site already bills its customers by Paypal Invoice and once paid the system generates a excel file with products the customer ordered. We want the checkout page to offer the customer a choice of either Credit Card or Paypal Invoice. The credit card processing company will be Chase Paymentech which has lots of documentation. Our goal is to ask for the customers information on the website and the response would trigger an event which delivers the product.. The current Paypal invoice system adds a 3.6% fee on to the invoice. So on the checkout page we would like to tack on 1.65% fee when the Credit Card option is selected. The Paymentech API documentation is located here: [login to view URL] We are looking for bidders with over 15 feedbacks and a minimum 80% completion rating. We only release milestones as work is completed and not as an advance to start work that may have a chance of being uncompleted. Thank you so much for your time and good luck bidding.