data feed for ebook store

I need a datafeed for ebook stores. This will update and change out the ebooks, at a set time we choose. I do not need a store design, just the datafeed. The storefront will hold paypal payement details, and the datafeed will handle delivery. any questions please use message board. I have included a mindmap of how i expect this to work. I am open to what database is needed, and what language. thanks Brian