A quick comment on spill beam shots. If you are taking pictures with a camera at a differing location from the light, they won't show the spill from a first person perspective, but would be better at indicating how well the light would work in a group setting, or flood as you say. It would be not so good at showing the perceived spill from the user's perspective, i.e., it wouldn't necessarily show how the light would look to the user.
If you could get your hands on a fish-eye lens and shoot from near the light, it would probably give a better feeling of the spill and light dispersion from a first person perspective, however I'll admit that wide angle (sub 10mm focal length, >90 degree FOV) and fish-eye lenses are not that common.
Regards,
Eric