API Development for Aviation Software

I need an API that streamlines several functions related to General Aviation management.

Core Functions:
- Quotation Generation: Create detailed quotations for clients.
- Client Record Maintenance: Keep comprehensive client profiles.
- Flight Briefing and Invoicing: Manage all flight details and coordination.

Quotation Details Must Include:
- Flight details
- Client details
- Cost breakdown
- Terms of Charter
- Notes regarding flight operation

Ideal Skills and Experience:
- Strong background in API development
- Experience with database management
- Familiarity with aviation industry software
- Strong attention to detail and accuracy

Looking for someone who can deliver a robust, user-friendly solution. Please provide examples of similar work done.