Should I use Dynamics or Sharepoint?

My client is an index fund which buys bonds of other companies.

My client wants to track many bond issuers, each of which have many issuing entities, each of which have many issues. Issuers also have many documents associated with it, each of which needs to go through a workflow before certain attributes associated with the document undergo state changes. There are also workflows to change the attributes of Issuers, Issuing entities, and Issuers. By workflows I mean some changes need to authorized by two people. They will get e-mails and they will login into pages on the system and authorize those changes. All changes to all the entities are auditable. There should be a REST/OData/CMIS API exposed by the system so that other systems can change the attributes of entities. All users should be authenticated by Windows Active Directory. All information in the system should be full text searchable. Lists of entities need to be searchable, browsable and filterable by its attributes as well.

Should I use Sharepoint or some Dynamics product to achieve the above?

Or should I go write an MVC Application to do this?