Thanks Jason, just a couple more things if you will then I think I'll have it all cleared up.
When you say the database is updated when the order is confirmed, does that mean that Paypal Pro will redirect the user back to the website, and not with Standard? And if so, does eCart configure itself for both scenarios? (I can't remember if I had to specify Standard or Pro during the eCart setup.
Another way to describe it, could you tell me if the workflows below are correct?
User submits order, is redirected to PayPal, chooses which method of payment and completes payment. The user is not redirected back to the website
User submits order, PP Pro is able to use the information sent over - name, address, etc, and redirects the user back to the site after the transaction is complete.
Sorry for asking so many PayPal questions, but I think I may have advised my client that PP Standard would be the best choice, being free and all, but the client needs a a fax confirmation which I need to do from the website - therefore, the payment must be confirmed before this is sent out.