Multisite user management

Hello, I just installed a fresh Wordpress Multisite, and I was wondering if any of your plugins were comparable to http://wordpress.org/extend/plugins/multisite-user-management/? I am going to be using this Wordpress network to create new sites for my clients, and I don't really want the websites to be interconnected in any way. I don't want users of other sites knowing about, or having access to any of the other sites, and I prefer not having any of the website themes available to any site but the one it belongs to. Can you suggest a compilation of your plugins (and/or other plugins if you don't have one available) that can accomplish this level of functionality, security and professionalism?

Thanks!