Using the REST API, how do you generate a hierarchical JSON response from Siebel?

Hi,

We are currently implementing Siebel IP16 for a client and they have decided to integrate a custom web front-end with a Siebel back end.  We propose to support the integration between that front end and the Siebel back end using REST and JSON.  As we gather information to support this approach there are a few points that we cannot seem to confirm/understand from the sources available.

1.  We would like to know how to configure Siebel to return a hierarchical JSON message to the front end when appropriate (e.g.  Return the SRs submitted by the user and the child activities and attachments associated with those SRs).  I've seen some information that suggests calling a business service that would get the records in seperate objects, then construct the hierarchical JSON message to return to the calling application.  I also believe it would be possible to have the front end application make 3 REST calls, the first to return the SRs, the second, the SRs related Activities and