Simple Google Checkout HTML API Integration

I need to integrate Google Checkout HTML API with a simple order page here: [login to view URL] There is no need for a shopping cart. One item at a time, no taxes, no shipping. The reason for the API and not the simple html integration is that I need to integrate Google Analytics and JROX affiliate tracking to the checkout. Instruction for JROX here: [login to view URL] It's a simple line of code to be passed. The server is UNIX with PHP. If you have experience and can do this quickly, please let me know.