158172 payment gateway

I want to develop a website with the ability to share its payment terminal with multiple sites. To achieve this, I want to build account management features around existing payment gateway to enable multiple users (merchants)share the same payment gateway/account on their sites. The management feature will be on the back end. please see [login to view URL] (example) On the front end, i will require a shopping cart that will be available for each registered user from their respective sites. services will be similar to [login to view URL] Please refer to attached document for more details, Thankyou.