Database/ website design

Looking to design a dynamic user-data driven, membership website which will send text messages to registered users, based on user content/ consent. Initially looking to have a yearly and monthly subscription basis, which could charge through PayPal, Google checkout, or Amazon payments. After successful proof of concept, and enough subscriptions to fund it- integration of Google Maps to add GIS component to the Members content Ability to integrate popular Social Media links a plus, as well as ability to demonstrate prior work. Specifically avoiding monetization of the site with advertizements- this will be funded exclusively through the membership cost. I don't really know how to describe the website concept without giving up trade secrets, so you must be willing to sign a NDA. Also, as this is my first attempt at freelancer, I'm not sure how the Budget structure works. I don't have the ability to make a large initial investment, but am willing to split membership fees 50% until... Target demographic: >10,000,000 users