I'm setting up ecommerce on the network and I'm trying to figure out if pro sites is a good fit. Basically we have some simple support plans right now here: http://www.softwiredweb.net/pricing/
I've configured Pro Sites for the two options for Basic and Pro but I don't know if these will get recurring payments or if they are manually applied for Stripe. http://www.softwiredweb.net/pro-plan/?bid=25
I think this plugin will work based on our offering and just restrict access to some themes and plugins.