OK, I will answer my own question. I just found out via the iFixit teardown that the charger is 28mm by 6.7mm, in case anyone else is interested.
For some reason once you see it, it's much smaller than I imagined.
Is there any difference between them really?
Can one of you lucky ones that have the sport watch measure the diameter of the charger? I am going to try and make my own stand to keep me from thinking about how long it's going to be before I get mine.
Yes. The 2m cable is longer than the 1m cable. ;-)