I have searched around but couldn't find an open source checkout that allows serious single product customization. I have a single product website I've built and simply would like to integrate a cart / checkout to my "Add to Cart" Button on my product page. The product comes in different sizes and colors so the cart must treat each product as a separate entity in the cart. I have some experience with PHP, JS, and SQL - can anyone recommend a game plan here?
Yes Free single page Checkout is now available in Magento connect, Swift Checkout http://www.magentocommerce.com/magento-connect/catalog/product/view/id/19525/