Im in the market for a new Gi bag and was wondering if someone could help out. I take the train alot to the dojo and need another messenger type bag thats waterproof. Im looking at the Timbuk2 Classical messenger bag. But im not sure if I should get a medium or large. Im carrying a Gi, hakama, belt, change of undergarments, and maybe one or two other small things. Dont forget I have to take mass transit to and from.