Develop Benefits Administration (BenAdmin) System on Salesforce

We are an employee benefits carrier. We need a very simple benefits administration system on salesforce. It must be HIPAA compliant. If you have built or are familiar with the functions of a benefits administrations system, great. Let us know. If you are unfamiliar with what a benefits administration system is, please take a look at some of the companies listed here: http://www.capterra.com/benefits-administration-software/. Why do we only need a simple system? It is not a product we will market - just one we will use. We need to administer participation, i.e. access and manipulate contact data, for only three benefits. We need to provide functionality and a UI by which designated users who are not a part of our company (we'll call them "outside benefit administrators") can access this system to add, remove, edit and otherwise administer general information and eligibility information regarding participants in our benefit products. We need to be able to send/receive (to/from outside benefit administrators and their organizations) large volumes of contact data through EDI's [and possibly as a separate/subsequent project via API's].