You have correctly identified several good approaches for illuminating the target. More info can be found
http://decibel.ni.com/content/docs/DOC-8923 in the lower right More section.
The speed of the robot and objects in the scene defines the speed of the flash. LEDs are a great choice for many reasons, but I suspect incandescent would be fine, perhaps even using something to build a shutter to hide the light.
The other approach is to use a known light color, again LEDs are a great pure light color source.
Greg McKaskle