Custom Payment Gateway API integration

Hello, I am looking for a coder who can take my current static HTML pages (see below) and integrate a payment gateway API. I will also need the person to fix an issue in the CSS with my php header. PLEASE NOTE: the site is a custom build and is NOT based on Joomla, Wordpress or any of these other out-of-the box solutions. ALSO, i can not use paypal API as I require a custom trial period. API information is available below. The selected freelancer will also be required to build a client transaction database and integrate it with my existing custom CMS. Sales pages: [login to view URL] [login to view URL] [login to view URL] [login to view URL] API information: [login to view URL] Please contact me if you have any questions regarding this job. Justin