I got the predator pack from this guy. Email him and he will set you up with what ever light you need. The pack comes with everything you need, lights, cap, extra batteries and charger.
http://shop.boondock-outdoors.com/
I have the Kill Light XLR 100 on top of the cap as a scan light and the Kill Light XLR 250 mounted on my shotgun. I pick up the eyes with the scan light then when they get in range I hit the switch on the shotgun that turns on the 250 light just before I pull the trigger.
What you do is keep the scan light on all the time from when you leave the truck until you get back. Keep the middle of the light high, you want to use the bottom of the light halo to light up the eyes. If you put the middle of the light on them it will be too bright and spoke them off, only do then just before you shoot,