Drupal site to mimic docusign

I am looking to hire someone to create a Drupal site to mimic DocuSign for an existing business. I will be self-hosting the website, so the freelancer I hire should be able to develop and implement this system without additional hosting services. Additionally, I am looking for the website to be designed with mobile-friendliness in mind, so it can be accessed by all devices.

Scope:
1. Install the Drupal site on the hosting
2. Set up GitLab or a similar solution for other developers to work simultaneously and commit their code
3. Install and configure. a theme provided by the customer.
4. Build user roles as follows: (Custom permissions will be provided by the customer)
Super-admin
Free user
Paid individual client
Paid corporate client - Admin
Paid corporate client - user
Document signer (unregistered)

5. Use cases: (prefer to use out-of-the-box widgets on the Drupal marketplace as much as possible)
Create a company profile
Create and initiate a document - Option to select where the signatures are required
Sign a document - touch screen signature modules, e-signature options.

6. Customized payment module for different subscription
7. Payment authorization
8. Notifications -
Text notifications (Need developer guidance on the module to use)
Email notification