Not sure what you are wanting here. But I would say build a CMS like Wordpress' back end. I have a wordpress.com blog, and a self-hosted one. Wordpress.com has a stats plugin, so I can check both blog's stats, via wp.com. I just select which blog via a drop down. The same goes for themes...

While that is a bit of a long winded answer, I hope you kind of get what I am saying...