PAY: Advanced Payroll Costing

My organization is implementing 12.1.3 Oracle EBS Payroll. We also have the Financial suite and Projects and Grants. We have a unique payroll costing method and would like to know how we could set this up. Here is the description of what we want to happen from out Accountant:

1)      All Payroll cost is allocated 100% to the employee’s home organization.  Regardless if any costing is charged to other projects or cost centers, these charges should be directed to home organization based on the Event type mapping defined in Payroll.

2)      A second journal needs to be created which generates the costing charged on their timecard to cost centers or projects outside of their home organization.  The amount needs to be based on the employee’s base rate plus the actual overhead cost with a couple of exceptions. The GL account needs to be derived based on the following rule: 1) If the home org and charge out org reside in the same fund then the amount should be directed to GL account  on the DR side – 54501 and 51991 on the credit side. 2) If the home org and charge