program the includes scheduling, invoicing, and many other elements

As a business owner, I'm looking to have a custom program developed that includes scheduling, invoicing, inventory management, customer relationship management, and task management. It must be compatible with both Windows and Mac operating systems, and have a complex and detailed user interface. The program should also have intuitive features to aid in managing and streamlining my business processes. I'm looking for someone who is an experienced programmer that will take the time to understand my business requirements, make thoughtful and knowledgeable suggestions, and create a custom program that meets all of my needs.