If I have one membership for drip-feed content, what type

If I have one membership for drip-feed content, what type of membership do I create that sells a single product? Once someone signs up, I'd like to offer them a single purchase product and protect it's content. It's easy to protect the sales page so it's only seen to drip-feed members, but what kind of membership protects the download page (and doesn't interfere with the drip-feed pages)?