Here you can look for the CMS thats right for you 😉. Sorry, no advice though. From my experience, the CMS's that are already out there offer the same things. Which drove me to make something as similar called a "Comprehensive Information Vault". Stores your information in a differant way other than SQL .inc files or .htaccess. Could "possibly" end up being more secure than .htaccess. Its a secret for now :p
Added: Not really advice but PHP Fusion caught my eye when I first started with CM Systems. Very clean & smooth looking.