E-Business Tax VAT Calculations on Services and Goods

Dear E-Business Tax Experts,

I have a following requirement on E-Business Tax.

My Client don’t want to VAT on PO Module but they want to calculate vat on Invoice.

Using PO matched invoices

Main Requirement is If they create invoice for Goods VAT should calculate 5% and If they create invoice for Services 5% Reverse charge should calculate.

Can anyone give me Idea how to achieve this.

Regards,

Narendra