I would recommend that you use PayPal Express Checkout. It is a more simple approach and has all the same capabilities. If you set up Express Checkout with eCart, it will automatically forward back to the pp_confirm page.
With PayPal Standard, you will have to go into your paypal account and set a return page and then set up a listener to determine if the transaction process went through or not. In addition, if you are using PayPal Standard, it is generally easier to just use the PayPal account to perform the order management.