Create a form in oder to let my client update informations on a Potential

Create a form in oder to let my client update informations on a Potential

I would to let my client fill informations into a Potential entry of CRM. here the flow I would like :

1 - A Lead fill a form on our website.
2 - Convert the Lead to a Potential
3 - Send a email to the Potential explain him we need more details in order to process.
We provide a link in order to get form with some Potential infos pre-filled.
4- The Potential fill the form.
5 - Save the data into the Potential.

Someone has already do something like this? How I can create a form with some parameters in the url that can be accessed without any password or login prompt. Les the user update the form and save into the Potential?

If anyone can help me, your welcome!