Importing and displaying customer-related data in the Customer Center

I have a cloud computing business which sells customers production (business) computing by the hour, eliminating the need for them to have an IT department or own servers.   The way we do billing is much like a cell phone or electrical company, which is usage-based.    I'd like to simplify the billing by sending an invoice with totals, and have the details available online to the customer in their Customer Center.

Our usage metering system can generate detail data for customers to my specification.   However, I need an architecture do import and display this data in netSuite.    I'd like to start small and grow the customization, so I thought I'd start with a custom record structure for the data and import it by CSV import, then display it with a custom search in the Customer Center.  I have run into the following problems I need help with: