Don't see why that would not be a great kit. K-3 is excellent at low light AF. Though honestly, getting good shots is at least as much practice, learning the camera, knowing the game and anticipating the action than it is a new camera. They shot great sports images with manual focus for a long time.
I got the K-3 on pre-order and have no regrets, it has been an excellent camera so far. The files are larger, and I find my PP is different than with the k-5 so I am having to change some things but all in all I am very happy.
18-135 is a great all around lens, my wife has one on her k-5IIs 90% of the time. I've no experience with the 70-200 but it is highly regarded.
One of the pluses of the k-3 is the larger files so you can crop a lot and still get a very usable shot.