Can you put your banking eft, bsb & account numbers on the sales invoice?

Yes. You can add it, execc.

You can add your banking info by adding a custom field to the sales form. If you wanted to add it only for Invoices, here's how you can do it:

1. Click the Gear icon, select Custom Form Styles.
2. Click edit on the invoice template.
3. Go to the Content tab.
4. Select the top field (for header) or the bottom section (for footer).
5. Click Custom field.
6. Tick the box, and enter a field name.
7. Click Done.

If you wanted the information to appear on all the sales form, please follow these steps:

1. From the Gear icon, select Account and Settings.
2. Go to the Sales tab.
3. Click the edit (pencil) icon of the Sales form content section.
4. You can enter Bank Acct No. as the field name under Custom fields.
5. Tick (✓) the Internal column. 
6. If you want this field to be included on the sales forms, tick (✓) the Public column.
7. Click Save.
8. Click Done.

You can also import your own invoice template in Word. See article How to Import Template Styles from Word.

By the time you're ready to match and categorise your transactions, you can check this guide: Download, match, and categorise your bank transactions in QuickBooks Online.

I'd be pleased to help if you have other concerns. Have a great day!