I have used both http://www.sharefile.com http://www.sharefile.com and http://www.leapfile.com http://www.leapfile.com for this exact purpose. I liked ShareFil

I have used both http://www.sharefile.com http://www.sharefile.com and http://www.leapfile.com http://www.leapfile.com for this exact purpose. I liked ShareFile better (UI), but both of them worked as advertised and would be ideal for your described scenario.