Newsletter Subscribers Setup in banner Zen Cart

my site is [login to view URL] I have a banner on the site that says "We now accept Google Checkout and all major Credit Cards including Visa, Mastercard, Discover, & American Express." I would like that removed and replacing it I would like to add newsletter subscribing functionality. I have installed phplist on my site already so should use that software unless there is a better alternative. It must be a horizontal subscribers box and button like image attached. when person enters email he is automatically subscribed to the list and kept on the page they are looking at. the confirmation should look like the image subscribed confirmation which is also attached.