How to setup Retiree Health program, upon Termination provide Enrollment, bill the ex-employee the p

Existing Employees are setup in OAB. 

Requirements:

When they are terminated...

* Track Retirees, Cobra ex-employees via OSB

* Do not want Life Events, hence use OSB

* the Plans offered are the same as for Employees - BUT will have different eligibility (so, can you use these Plans on a new Program with Elig. Rule?)

* allow ex-employee to Login to Self Service and manage enrollment

* bill the ex-employee (they are NOT on a payroll);  how to?

* with Cobra, how does the 18 month maximum month coverage get managed ?

Does anyone have a white paper, setup document, or recommendation on how-to?

Thank you.