Looking for an easy tool to sell links


I have a lot of website and i sell a lot of links on all my websites. Now i want a tool to make it a little bit easier.
So i want a script where my clients can login -> fill in the website link they want on my website -> the categorie -> the period and after that they can pay for the links.
In their client panel they need to have an overview of all their links and when they will expire.
In the admin we just need an overview of all the links.

Is there an script or system that has the functionalities? I only found this on envato.

Thanks for helping!