Plugin for a productized service

Hello,

I have just launched a productized service. I would like to setup my website to allow clients to create an account, purchase a subscription (able to be cancelled, billed monthly but with the option to pay in advance for a discount).

Preferably able to allow clients to upload documents and files and perhaps open support / job tickets, though that might be a different plugin. And ideally I could then feed information to their account, create reports, send notifications, etc.

The closest business model would be – http://wpcurve.com/ and http://designpickle.com/

Most of the advise i’m finding is of these “membership sites” which are designed just to lock content behind a subscription – not quite what i’m after.