Automated key/licence code delivery site

Hello, thank you for taking a look at our project. We are looking for someone who is able to automate selling a licence code for software. The code in question will be the only item on the entire site. Effectively this means we're looking for a single item webstore of which the delivery is automated through e-mail. The licence code is a scanned image in .jpeg format and should be added to the automated email as attachment. As each licence code is unique its extremely important each code will only be handed out once. However an administrator should be able to view what code has been given out to which costumer and the costumer itself should be able to lookup his previous orders. Payments most likely will be made through a Payment gateway(psp), after the payment has been received the email containing the licence code should be sent out. We'd also like to give out discounts for returning costumers and for ordering multiply units. On top of that we'd also like to be able and make promotional discount codes. The site should be SEO friendly and should be able to have multiply languages. Search engine optimization is not part of the package we're requesting. However if you're able to, please inform us with your bid on the total package (webstore and SEO).