reasonable deployment scenario...?

I wanted to describe our deployment scenario, and make sure Snap Deploy is the right product for our needs, if anyone can give some feedback. At first glance, it sounds like it solves many of our deployment issues.

Say, we have 100 different customers at different physical locations. At each location, we'll want to deploy an instance of our application which requires multiple physical servers (between 2 to 5, on average). All servers are running Windows Server 2008 R2.

The first server will be a domain controller, creating a private domain (not associated with customer's domain infrastructure). Each additional server will be a member of that private domain, and have its DNS point to the domain controller.

We'll install SQL 2008 R2 Express onto that first server (DC) image, and our software and prerequisites onto all server images (including the first).

My assumption is that we'll need two 'prototype' server images, one for the first server (DC) and one for each additional server. Would that sound like the proper approach?

Also, is there anyway to use an external host server for the images (i.e. hosted by us, outside of the customer data center, accessible over Internet)? It would be great to have one location where we host all the master server images, and for each new customer, they just pull from this one location to install.

Thanks,
Kirk