Shopping cart

I am looking for an ASP.NET/C# programmer or group to develop an online payment solution for my companies website. The payment processing application should function both for point purchase and for direct creditcard/debitcard processing. The payment should allow users of my website be able to purchase points that they can use to buy services on the website (E.g. www.istockphoto.com). The payment system also has to allow users who just want to pay for a service be able to input their credit or debit card to make payment. It has to be written in ASP.NET/C# with an SQL database and authorize.NET as the gateway provider. Thank you.