For low-light and fast action there's Manual Focus which is fail-safe for any light conditions, Pentax has a "focus peaking" assist for MF, and AF can be temporarily disabled with a push-on/push-off button to ascertain and maintain the focal plane on multiple shots.
If you still want to use AF in low-light, fast action non-human subjects, use a small flashlight as an AF assist. I say non-human subjects because pointing a flashlight at anyone may be annoying.
Extend one leg on a tripod to make it a monopod.
Continuous drive speed and fast Class 6+ memory speed for quick turnaround on multiple shots.
Last edited by Heliotrope; 09-07-2012 at 08:08 PM.