238778 Google Checkout API

I need a Google Checkout API written so that when a customer clicks my Google Checkout Buy Now button on my website they are forwarded to a page that contains my digital product download link and/or they are sent an email that will contain my download link. So the process is: 1. Customer clicks on the Google Checkout button 2. They are forwarded to a web page on my domain that contains the download link and/or 3. An email (that I will write) is automatically sent to them, which contains the download link. Ideally they would be forwarded to the download page and they would receive the automated email message containing the download link and instructions on how to download. I need this process to be seemless. It is very simple and I would like to keep it that way. I want it to be very easy for the customer to follow. You will probably need experience with Google Checkout in order to do this. If they are forwarded to a download page I need that page to not be accessible by non-buyers. You must make sure that only people who have completed the purchase (and the money has been charged) get access to the download link. If they cancel the purchase they will need to be forwarded to cancellation page. I'd like someone who is good with this type of work as I will probably need more similar work of this kind completed in the future and I will probably use the same person. Please feel free to ask any questions. Thanks, Chris