Need TreasureChestCart with Paypal Subscriptions protected subscriber content

I’m planning to use treasure chest cart for a project for a client. They need to manage Paypal subscriptions where the user pays a annual fee to have access to certain documents/pages in modx and also to get access to certain files (pdfs, etc.). We don’t want someone who has the URL to forward it to a friend and let them download things for free without being asked to logon and have it check their paypal subscription. What approaches do you recommend to doing this with treasure chest so that it will manage the paypal subscriptions of signing up for a subscription, renewing subscriptions, stopping subscriptions (all via paypal) and then controlling access preferably to the modx webusers and webpermissions to only allow users with currently valid subscriptions to access this content?