My suggestion would be use rsync over ssh to sync your files up to the server. Then for your clients install extplorer and apache, setup accounts however you feel they need to be setup (directory wise).
You should be able to control write access either through extplorer or through permissions for the webserver user (owned by you, group same as webserver 644, etc.)
You can find extplorer here:
http://extplorer.sourceforge.net/ it's a pretty spectacular interface for getting to files in a pretty gui and offers most of the client side features you're looking for.
I would suggest running it in FTP mode and having it connect back to the local ftp server so someone entering a direct url can't get to files you wish to be inaccessible.