Private Videos

This is for a new site I am going to be building for a client does anyone have any suggestions on how to set up streamed video for the clients to offer to their students and do you know if there is anyway that the individual video can be set to private (just for the user to download) this seems complex given its going to be a video from U Tube or one of those 3rd party channels? 

I think you might want to look at Vimeo, see if it fits your needs.