You can use the Work Order transaction type (instead of Invoice or Layaway) in the payment window.

Transaction Type Definitions

 

To receive extra payment after the initial Work Order transaction:

Receiving Outstanding Payments

 

Recall the Work Order transaction, modify or convert to invoice:

Recall Transaction Functions

 

If you track the status of each item, use the advanced features:

Advanced Functions for Layaway, Special Order, Work Order

 

To print custom form:

Printing Custom Forms for Transactions