Wrapping My Head Around My Vision

Okay, I think I'm on the right track but I could really use some help getting my head fully wrapped around making what I want to work. And I think a lot of this is being remedied as we speak with your Pro Sites plugin that is getting prepped for release (curious if you've decided on a release date btw?). Anyway, here is what I want to do:

1) User signs up to be a part of my network, they get charged an initial sign-up fee for this (I'm offering certain customizations and 'bonuses' as part of the initial setup)
2) User gets billed 'x' amount per month depending on the package they sign up for. Each package has specific themes, premium plugins, and additional functionality available to them. We'll say there's 4 different packages: Copper, Silver, Gold, Diamond
3) At any point, they should be able to upgrade to a higher or lower version depending on their needs (ie. someone decides to go from Gold [having their own e-store/affiliate program] to Diamond [having their own membership site that also has a e-store and affiliate program])
4) Based on whichever account they have, it should have the ability to utilize a Blog Template upon creation of the site. For example, a Silver level user may get access to Gravity Forms (and I don't want to have to put in my Developer Key for every user), whereas a Gold user may get access to MarketPress and I would have pre-defined page-templates (ie. Terms & Conditions, Shipping, etc.) that they simply need to fill their information into for this.

It seems to me like much of this is already basically being sorted out in the Pro Sites plugin that I've been playing around with a bit tonight except for the Blog Templates portion, but perhaps I'm just unaware of how to integrate these properly. I see the normal Blog Templates option under the Super Admin Settings area... but I haven't seen anyway to automate this... am I missing something?

Anyway, I could really appreciate some guidance on the plugins/flow I should be using to accomplish this. I also have several other premium plugins like Gravity Forms that I could potentially use for User Registration as well if that helps at all.