Hello I just purchased the new Sony DSLR A100k. It seems to be what I was looking for except for taking pictures of my daughter when she is doing gymnastics. Most gyms that I have been in have low light and you can not use a flash. I have the ISO setting at 1600 and that helped some but I can not freeze motion at all. You know legs and arms etc are real blurry. Any way does any one have any recommendations on a good lens for this camera, low light indoor sports.

Any suggestions or recommendations would really be appreciated.
Thanks
Mark