When I bought a 200' roll of Eterna 800, I simply went into a totally dark room, opened the movie film can, grabbed about 20-25 feet of the stuff and spooled it into the bulk loader. Repeat as often as needed.

I know of one commercial lab in the U.S. that will still develop ECN-II film spooled into still film cartridges, and that's The Camera Shop in St. Cloud, Mn.