Data Format and Exchange

We sale books on internet through websites like eBay and Amazon. We have current inventory management system that automatically updates inventory (add/update/delete) data on various venues they support. The inventory update data is available on FTP in simple tab limited tab file on hourly basis. I can send sample. It is plain text file with all of contact information.,. I need program to, 1. Process simple text data on FTP and convert into data format required by additional website that I want to sale on. 2. Objective of program is to support more websites than supported by our current inventory management system. 3. I'm interested in extending our data to [login to view URL], [login to view URL] and [login to view URL] for now. All of this venues have well defined help file and instruction on format of data they would need. 4. Most of the help information is listed here. [login to view URL] 5. Programmer would need integrate back for orders received from additional venues back into [login to view URL] as well. 6. We will need to build database of about 3-10 mil items that can be viewed and manipulated for future extensions of other venue as needed. I'll be fine with any database choice. 7. I need a decent usable GUI for program with some critical information about data and activity be found. I would prefer that entire solution be hosted on web as much as possible. 8. Program need to be well tested and well programmed and decent GUI so that it could be operated by a an employee with very limited knowledge. We can not take any program to website unless fully tested and verified. Thanks for your interest in our project. We look forward to working with you. Regards, Rupesh