Whilst it all seems fun, I would be using my wisdom well in suggesting you don't. I would use one that's well supported, because it means a lot less work for you. Try something such as Zend Framework, or maybe Cake, or Symfony. Those are well established, and have done all the hard work for you.
Nonetheless, it's good to learn how to write such stuff yourself, as it fills your mind with knowledge.
The man who comes back through the Door in the Wall will never be quite the same as the man who went out.