maybe this is something for you:


http://digital-photography-school.com/mastering-panning-to-photograph-moving-subjects





or google "panning"


I would go for the 100-400 mainly because of it's versatility and IS mode 2. Your tripod will be an excellent IS mode 2 as well []Your own 70-200 might do the trick, but I doubt it that you can be close enough to frame it nicely. You don't want to crop away 75% :P


Good luck! And maybe show us some results later on??[]