Private trackers will probably be your best bet imo if you want to stick with torrents, any popular genarl private tracker will probably be enough. If they dont have it already you can request it and someone will probably have it uploaded in a few days (unless its something really obscure). If you can seed long term and maintain a good ratio then getting into more specilized tracker wont be a issue. If you want I can check if I still have an invite for Torrentleech, they might have what you are looking for.