Since E-junkie is a centrally managed eCommerce solution, we do not have an option to install the system on your server so that only your domain will shows during the entire process. With E-junkie, the buyer would go to our server when adding products to the cart and then to one of the payment processors we integrate with to pay for the product. After that if the product is a downloadable file, unless you setup a redirected thank you page your buyers would once again come back to a page on our server to get the file.
You could use a redirected thank you page with our Buy Now buttons and your buyers would never see E-junkie's name, but they will only be able to purchase one product at a time.