Hello, I completly understand what you want, yo can go through my portfolio and you will that i the indicated for this project. I have knowledge with PHP, Ajax, JQuery, Html5, CSS3. the necessary to create a web entirely dinamyc and interactive. In your CMS also the part of php, login, register, the settings etc, i will use the other language to do the magic, that make improve the experience of the user. Ajax will do the site more efficient, the won't reload the page for do something; it make the site quick.
If you're interested, please contact me.
Have a nice day.