Sales Kit Tab

I am wondering if anyone has added the Sales Kit Tab from Order Entry to the Invoice Entry Screen? Our AR group does not use sales order and creates MISC invoices. I have customers that have tiered pricing. In order to make sure the invoice is correct, we create a sales order, update the sales kit appropriately and then create a MISC invoice from the sales order. The issue is if they need to make a change to the line item, they have to go back into the sales order and correct. If they had the ability to change the sales line and kits in the invoice it would be much easier.

Charles