I'm definitely not an expert here (far from it) but this sounds a lot like what achow101 has developed
here. It's a tipping address that generates a new one after each tip is sent.
Well i think it's a little different because on "Bitcoin Tipping Addresses" you need to enter a list up to 1000 addresses. It will basically pick a random address from the one of the list after a tip/address gets balance.
@monbux wants to generate some kind of "invoice" that generates a unique address (with json-rpc connected to the wallet), and it gives the amount of
BTC that user needs to pay. Once the address gets the amount of
BTC, the invoice will switch to "paid" on Database and it will redirect to content or something (depends of what is the invoice for).
I think it's this..