Simple Invoicing & Inventory application

Need simple Invoicing & Inventory application(for Windows XP) Invoicing +product database +customer database +reporting. Program can use standard DBF Foxpro files for database or something else. Delphi application is most preferable. Must me designed as standalone executable(containing all resources), preferable if store data in .ini or .config files, not in registry. I need basic functions: - prepare Proforma-Invoices - prepare Invoices (configurable invoice layout) - additional tax and discount can be configured - linked with product and customer database - maintain product's database(add products, prices, etc) - maintain customer's database - track payments(paid/not paid). - create simple reports(total sales, sales per customer, etc) - ability to export invoices & reports into MS Excel