I'd like your opinions on picking either a Canon EF 70-200mm F/2.8L IS USM or the 300MM f/4L IS USM. I will be picking up the 1.4 TC with either lens purchase. I attend the annual Airshow at Andrews Airforce Base in MD. and also the airshows in NJ. Would the 70-200MM be to short for taking photos of aircraft in flight? Thanks for your input.