Landing page and Facebook Login

Hi,
First thanks for Vantage, the result you have achieved is amazing, I can’t speak high enough of it. Really been enjoying playing with the site. Such great features and the details that can be tweeked in the themes have really come a long way since I last designed with WordPress 9 years ago.

Down to business:
I have a one page web site landing page at the bottom, which I ask for the user to fill in a Contact Form 7 with email, contact details, phone numbers etc… I am going to be meeting these people in person. It’s only going to be serious people that fill it in. I want to see who I am going to meet so I want them to press & accept a Facebook login subscribing the person to the site before the contact form can be submitted.

In simple form:
1). The person will load the landing page.
2). Read and scroll down.
3). Call to action:
See the contact form 7 and if they want to send it be asked to first login/subscribe with Facebook credentials.

What I want to achieve:
1). Have the visitor subscribe for future updates.
2). I be able to see the users Facebook profile for a photo of the person I will meet for business purposes, character assessment etc.