Flex datacaching component (Java Webservice, Flex Client)

Hi, you create a Java webservice and a Flex client. The client requests data from the webservice. All receieved data is permanently stored in the client cache. The client then regularly requests updates from the webservice. When an update is requested only the updated or newly added data are sent. See the attachment for detailed functional and non-functional requirements. When bidding please provide some references and a very basic concept for your solution, so we can rate your design. Thx Danny