Is there a way of delivering the data over a simple p2p network - in a decentralised way - much like LN (where you are guaranteed payment for your work - hence more likely to offer your services) ?
The problem is when you are adding the payment option in this design. First you have to decide whether this is a simple file sharing between peers (like Torrent) or is it a file selling between a content creator and his customers.
In either case I don't see any reason why you need a middle man (router) like LN since the file is only held and stored by the owner and nowhere else and he is already uploading it every time someone wants it.
If it is file sharing them it is just a matter of knowing the IP address of the one with the file and connecting to it. Basically P2P Torrent network instead of being a semi-P2P Torrent network (eliminating trackers).
If it is file selling it is the same as before but you only need a way to ensure payment, a multi signature scheme might work here.