Hello there david,

Let me help you with this.

There's currently no option to show the line item description on the invoice and the payments, on a single report. You'll need to pull up the Sales by Product/Service Detail report (to show the line items) and Transaction List by Customer report (to show the invoices and payments applied against it).

On the other hand, here's how you to customize the Transaction List by Customer report to show a single/specific customer:

1. On the left pane, click Reports.
2. Search Transaction in the Go to Report search field, then select Transaction List by Customer.
3. Set the correct date range under Report period.
   
4. Click the Customize button.
5. Click the arrow beside Filter.
6. Under Customer, select the customer you want.
7. Click Run report.

Let me know if this works for you. I'll be here if there's anything else you need.