Custom-built paywall for Wordpress site

We run a subscription-based website on the Wordpress CMS. Our current "off the shelf" paywall is not fit for purpose and we are looking for one custom built to our requirements. We require the ability to: - Put all of our content, except the index page, behind a paywall - A customisable limit on the amount of free articles a non-registered user can view each month - Various, customisable member tiers which determine how many articles can be viewed by registered members - The ability for non-registered users to view the first paragraph of stories before being prompted to register or sign in - The ability to create coupon codes and hidden tiers for promotional subscriptions - The ability to give free trials to users - The ability for users to gift a limited number of free reads of articles per month to their friends through social media - Integrate the subscription database with MailChimp - Port the existing subscriber database to the new paywall - Payment integration with Stripe and Paypal, plus ability for simplified registration process and Apple Pay - Articles to be shown in search engines despite paywall - Create reports on subscribers - Let the reader know how many free articles/posts they have left before they need to subscribe - Light server load running paywall script - Fully customisable subscription options page - Ability for user to be redirected to article if they sign up to paywall through an article prompt - Ability for registered users to be remembered and not prompted for sign in again for one month - Other common features associated with a general paywall/subscription system The current paywall in existence can be viewed at https://www.thetwopointone.com.