I'll disagree and say IS is essential despite the shutter speed. When shooting such small, fast moving things while zoomed to the max, the field of view is quite small and thus IS or VR will be a big help in stabilising the view through the viewfinder, especially if the camera/lens combo has any weight. The more zoom you use the more IS will help.

I would suggest a 70-200/2.8 IS USM +1.4TC which would still give 280/4 at worst, which should be fast enough for focusing on these things with a good camera technique.