I recommend http://getkirby.com/ http://getkirby.com/ (Not affiliated, but a fan.) It's worth the $39, but you can try it on a non-public site before you buy.

I recommend http://getkirby.com/ http://getkirby.com/ (Not affiliated, but a fan.) It's worth the $39, but you can try it on a non-public site before you buy. It's incredibly simple, powered by plain text markdown files, easy to extend, and there is a "Panel" plugin that gives a very basic backend. Very little setup since it runs on PHP and without a true database. You can also connect it with Dropbox if you have the server permissions, to make editing files even easier.