As regards to an ordered bittorrent, we're planning to implement and test RFC 7574 - the Peer to Peer Streaming Peer Protocol - which is a high level design for this sort of ordered p2p delivery.
Where things get interesting, and there are open questions, is whether or not to incentivize the delivery with payments. This can be done using state channels as you mentioned, or checkbook contracts. The argument for this is that you create an equitable and fair structure with incentives to get people to participate in seeding and relaying content. The argument against is that peers are already willing to trade bandwidth in a tit-for-tat way because they're incentivized to actually view the content, and adding the payment overhead means that consumers couldn't even participate unless they had the token/payment mechanism.
It seems like the right feature that people want is to be able to pay to increase reliability of their stream. This is incentivized seeding or incentivized relaying, like Joystream. We should try to design incentives that bundle this value prop into the network itself.