Sales Order KITs Solution: HOW can have pricing/billing on header but deliverring on item

Dears,

Our company needs to process KITs in sales business. We have created sales BOM, and wish to pricing and invoicing only on header material, but deliver at item level.

I have tested sales item category TAQ for header, TAE for item, but it seems not work - when create F2 invoice, it always check the item level category TAE not for billing....

Could anyone helps here? TAE/TAQ supposed the standard solution for that scenario, right? why it doen's work here?

regards,