Just a thought, I've been closely following the development of a game called Project Zomboid, and when the dev team had to work some multiplayer issues and steam integration, but all the team was busy on something else, they hired help from General Arcade as an "outsider" developer.

It helped them a lot, especially for the steam integration, maybe something along those lines could be done for the development of a matchmaking system you'd explain beforehand. But then again, it's just a thought ^^