Canon 300mm f2.8 IS vs 200mm f2.8 for indoor events

Hi,

I am trying to decide between these two lenses. I will be using the new lens primarily for taking indoor show-choir pictures and jazz-band photos of my daughters. (also some indoor tennis photos). I shoot w/ a d5M2. The lack of IS on the 200mm concerns me. I will probably try to hand hold whichever lens I decide on. I'll probably be shooting at 1/125 second, and whatever ISO required to achieve that. The extra reach of the 300 would be nice but not critical. From what I read, the IQ is excellent for both lenses. Comments appreciated. Thanks.

Mark P