Landing Page/Squeeze Page

I need a stack to be used in conjunction with an existing web site; to act as a door keeper. The stack should create a form that will request a viewer’s email address. After entry of the email address, the form should disappear and give the viewer access to the content on the existing web page. I have found count-down landing pages or simple stand-alone squeeze pages, but no squeeze page stack that will work in conjunction with an existing site.
Does anyone have any recommendations?

I can’t say for sure but Doobox’s Splash stack may be able to do this.

I don’t have Joe’s new Call To Action stack, but there may be a setting that forces a user to perform an action before they can move on…