to get the order form bindings on the confirm page, go to the bindings panel, click the plus button and select Form Data, click the folder icon and select the order form page.
you can use either the set session value behavior for eCart or for cookies toolkit, they both the exact same thing and write the exact same code.
Yes, by checkout page, i am referring to your order form page, I'm a little to used to talking in terms of checkout and confirm page i guess ;)