Hi, in my best ultra-newbie judgement I thought this would be the best forum to ask this, but by all means please move if I'm wrong.

I need a good File/Document Manager that I can offer as an additional option for some of my hosting clients. The idea would be to use it as an off-site backup slash way to access documents out of the office. I would like to offer it by the office, or by the individual members of the office (mostly real-estate clients). In the case of the office, an easy admin interface would be nice, and security is crucial.

I really like invision power file manager, but it seems like the security could be better being that it just uses .htaccess for folders and users must remember to 'lock' the folder themselves.

Does anyone have any recommendations?