I use strongbox on my sites and have to say its the best so far. I also use sitedepth for content management because I found that one to be the easiest and best as well. Correct me if I'm wrong but I believe if you order SiteDepth now you get Strongbox for free... contact Omar and tell him that Terry sent you.
http://www.strongboxxx.com
http://www.sitedepth.com/contact.php
Good luck!