I hate to say it (given the currently active thread about merging citations affecting the data generated by the Form gramplet) but a Citation variation of Form would seem promising.
Create a Citation form that adds a family of custom Attributes to Sources and/or Citations. Then create Cite plug-ins (with a CSL parser as a possible choice) that use those standard attributes to write more expansive citations.
Of course, Reports (or Books) would have to be adapted to choose a Cite plug-in.