There's trade-secret, but I'm not sure how it works.

By paying an invoice, you are essentially buying the preimage, right?

Request hash of the data you want from nodes who signaling they are seeders. They make an invoice using the hash of the file or a chunk of the file. The preimage is revealed when you pay the invoice. Nodes routing the payment would be incentivized to store these preimages, too, if they were revealed to them. (This relates to what I was saying about preimage reuse.)

Searching for seeders with they data you want could work similar to lightning escrow.