Setting up a multisite subscription service

I'm setting up a multisite wordpress install so that I can sell subscriptions for domains.

What I need is this:
Subscription/Membership plugin through PayPal
Plugin for top level domain management (multisite with lots of domains)
Support Ticketing System

I'd like users to sign up and instantly have their own site.

I've signed up with you guys specifically for this but I don't see an obvious first foot forward.

Can you help?