Let me elaborate on some details of how estimates work. This will guide you on what you're going to choose.

Intuit is committed to providing you with the best experience based on your feedback. That's the reason why we're able to produce and improve a new layout for your sales forms. 

As mentioned by my colleague @Bryan_M, you can use the old layout if you don't want your estimates to be automatically converted once the customer accepts the form. However, the request to deposit function may be unavailable. 

But if you still want to use the new experience, you can just send a PDF file of the estimate directly through email to ensure that the customer has already an idea of your estimates total amount. Then, once work is done that's the time you can send the actual estimate so it will be converted to an invoice.

In addition, after you've already paid the invoice, QuickBooks downloads the latest transactions automatically. Learn from this article on how to categorize them: Categorize And Match Online Bank Transactions In QuickBooks Online.

Let me know if you have any other concerns about estimates. I'll always be here to help.