WordPress Multisite w/Paid Subscription Options

I have configured my WordPress site as a multisite using subfolders and I’m considering how to configure it as a monthly subscription site using Paypal where users will be able to sell their own products.

I have 2 ways (so far) of thinking on the subscription model.

1) Users are not able to create a site without being paid first. They can register as Subscribers to the main site. Maybe they can post comments and/or reply to others’ comments. If I go this route I’m going to need a way of allowing the registered user to purchase a monthly subscription. At that time I will have to provision their site.

2) Users can create a site without paying, but will not be able to sell their items using their site.

Regardless of which way I go on these 2 options, I want to offer different subscription rates – 1 month, 3 month, 6 month and 1 year – each with a price break. On top of the subscription time period, I am considering that there might be other terms. Like they can subscribe to a basic plan where I will get a percentage of their sales (3%-5% maybe), and a more costly plan where there is no percentage to me.

I’m hoping for a subscription plugin that will be smart enough to expire accounts and will be able to send correspondence to the user. Such as a notice of a pending auto-renewal, or that the subscription has actually expired, their credit card could not be charged, a receipt that it was charged, etc.

Is anyone aware of a WordPress plugin that will do some/most/all of these things? Or does anyone have an idea of how to go about this with multiple plugins?

I’m just researching options right now, so I am all ears to ideas and suggestions!