.....how good I am going to be at loading exposed film onto the reel while in a changing bag. That is really what worries me the most now.

I dont have my reel or the bag yet. This weekend a colleague of mine is bringing me a Paterson tank and reel from the states. I am going to buy a bag here in China as well as a few cheap rolls of film to practice on. Hopefully this goes smoothly because the rest I know I can take care of!

Is there any particular size changing bag that is considered a minimum for 120 film?