Are my email subscribers the same as my followers.
Your subscribers are those who subscribed to your blog or individual posts via email. I can move those over if you move your blog to a self-hosted installation of WordPress.org and install the Jetpack plugin. Those readers who follow your blog via WordPress.com Reader cannot be transferred at this time, but then follow your new blog.
Can Suburbia be migrated to my new WordPress.org, again with the subscribers and all the comment history?
Themes designed for WordPress.com can only used on WordPress.com. However, there exists a version of Suburbia for self-hosted WordPress blogs, you can check it out here: http://theme.wordpress.com/themes/suburbia/
Note that the theme, the subscribers, and the comment history are all different (independent) parts of you blog. You will need to install a theme of your choosing at your new host. For subscribers, I can move over email subscribers for you as described above if you install the Jetpack plugin and connect it to WordPress.com. More about Jetpack: http://jetpack.me
As for the comments, you can export them as part of exporting your site. See here for more information on moving to WordPress.org: http://en.support.wordpress.com/moving-a-blog/#moving-to-wordpress-org
You might be interested in our Guided Transfer Service, where a Happiness Engineer does the work of moving the site for you: http://en.support.wordpress.com/guided-transfer/