Question Regarding a Collection of Membership Sites (Networking Multisite?)

It was difficult to come up with a title for this thread, because it may be a bit unusual, and I apologize if this has been asked before since I wasn’t quite sure what to search for.

I have an idea for a collection of sites in which if you purchase a “premium membership” for them (say, using the s2Member? plugin) that, depending on the level you pay for, you would be able to enjoy the benefits of that across either a single, or multiple of the sites in the network.

This brings up the question of how to do such in the easiest manner possible. I’ve been reading up on networking multisite WordPress, but I’m unsure if I will be able to successfully put that together or if it would do what I am looking for it to do. I also read deeper and noticed that it was a bit more complicated if you have multiple domains, of which I would have, as it is a collection of sites. I also have no need for the members to have their own sites, nor am I sure I would be used much of the BuddyPress features, so I’m not sure if I need the members to have their own blogs (although, that would be nice), or how that would conflict with the rest of the site.

I understand that my description is a bit complicated, so please feel free to ask me any additional questions so that I may give you a clearer understanding of my intentions, but basically, I’m curious 1) if there is a way to create what I am looking to do, and 2) what the best way of doing it is.

Thank you in advance for your assistance!