Change wordpress cart

[login to view URL] would like to change our shopping cart from our platform WordPress; and works like this page: [login to view URL] so adding products looks simultaneously without refreshing sidebar (AJAX) 2. We would like to a person make a payment, the first thing the system do it is request an e-mail address and fill out all personal information realated to the customer, so with this the system keep all the previous data tha the customer previosuly filled out by creating a generic password. Could you guys check this page out as an example [login to view URL] Our website is [login to view URL]