Requirements:

• User Management: Ability to add, edit, and remove users with different access levels (Admin, Sales, Support).
• Lead Tracking: Track leads from initial contact through to conversion, with status updates and notes.
• Sales Pipeline: Manage sales stages, set up reminders, and track progress.
• Reporting: Generate reports on sales performance, lead conversion rates, and customer interactions.
• Integration: Integrate with existing email and calendar systems.
• User Interface: Clean, intuitive design suitable for non-technical users.
• Support: Provide documentation and basic training for staff.

Deliverables:

• Fully functional CRM system
• Source code and documentation
• 1 month of post-launch support

Timeline: 4 weeks

Frontend Technologies:

1. HTML/CSS: For building the structure and styling of the user interface.
2. JavaScript: For interactive elements and dynamic content.
3. React.js / Vue.js / Angular: Frameworks or libraries for building a responsive and user-friendly front-end.

Backend Technologies:

1. Node.js / Express.js: For server-side development and handling API requests.
2. Python / Django or Flask: Alternatively, Python-based frameworks can be used for backend development if preferred.
3. PHP / Laravel: Another option for backend development if more suitable for the project.

Database Technologies:

1. MySQL / PostgreSQL: For relational database management to store user data, leads, sales, and other CRM-related information.
2. MongoDB: If a NoSQL database is preferred for flexibility in data storage.

Authentication and Authorization:

1. OAuth / JWT (JSON Web Tokens): For secure user authentication and authorization.

Integration:

1. Email API: Such as SendGrid or Mailgun for email integration.
2. Calendar API: For integrating calendar functionalities (e.g., Google Calendar API).

Reporting and Data Visualization:

1. Chart.js / D3.js: For creating interactive charts and graphs for reporting purposes.
2. ExcelJS / Pandas: For generating downloadable reports, if needed.

Development Tools:

1. Git / GitHub: For version control and collaborative development.
2. Postman: For testing API endpoints.

Deployment:

1. Heroku / AWS / DigitalOcean: For hosting the application and database.
2. Docker: For containerizing the application if needed.

Other Tools:

1. Swagger / OpenAPI: For documenting APIs.
2. Jira / Trello: For project management and tracking progress.

Support and Documentation:

1. ReadTheDocs / GitHub Pages: For creating and hosting documentation.
2. Loom / Screen Recording Tools: For creating training videos for staff.

These technologies should cover the core requirements for building a custom CRM system, from user management and lead tracking to reporting and integration.