Hello, yogi4. 

At this time, the option to customize the Purchase Order layout, and style is unavailable. You can only customize the sales form (Invoices, Sale Receipt, and Estimate) in QuickBooks Online. 

We always welcome ideas from customers that can enhance our software. Customizing the Purchase Orders is one of the most requested feature. Rest assured that our Product Development Team is working diligently to have this added in our future updates. 

In the meantime, you can visit our QuickBooks Online Blog to see what's new about our product updates and feature enhancement. 

If there's anything else I can do for you, don't hesitate to leave a comment below. I'm always here to help. Have a nice day!