How to work with Average Cost in Manufacturing

I am on E1 9.1. In my company we have the following scenario :
.Cost components: A1, B1 & D1
.We must work with weighted average cost for both purchased and manufactured items, to attend local regulations (inventory should be valuated by WAC).

For purchased items I intend to work with average cost offline – cost method 02 (R41811);
For manufactured items I intend to work with standard cost – cost method 07 and have a customized routine to run on month end, with the following features:
.calculate work center actual taxes based on the G/L balances of the expense accounts (labor and burdens costs) -  total amount of expenses should be absorbed in manufactured items,  ;