Being in your place, the OP, I'd have a deal with hosting-marketers.com, they are the best in delivering quality hosting for video websites, they have narrow specialization in this realm.
Very few hosts offer this kind of service, first because you need a very qualified customer support team, and second the server must be high end servers with loads of RAM and 1 giga port or even 10 giga ports. (10 giga bit per second).