Magnus Billing System Development

I need a comprehensive Magnus Billing system that includes:

- User Management: Specifically for customers.
- Invoice Generation
- Payment Processing Integration

Customer data to store:
- Personal Details
- Billing History
- Service Usage Details

Ideal Skills and Experience:
- Strong experience in PHP development
- Familiarity with billing systems
- Experience in user management systems
- Knowledge of secure payment processing integration
- Database design and management skills

Please ensure the system is secure, user-friendly, and scalable. Looking forward to your bids!