It's an interesting idea. I don't think a service like this exists, primarily because it's a lot of work wrangling everything that broadcasters want, and every one is different. What they will require, and all of the different variations of things, there are so many variables. I've been tasked to do this for various films that pass through my facility, and we basically do them as one-offs for each request. If you get a hold of specs for a few networks, you'll see what I mean. You might want to get in good with a trustworthy post house and strike up a deal for them to handle all of your conversion and material delivery requests, but I doubt anyone would do this as a flat rate or project rate. The requests are usually pretty unique and therefore billed individually.