Id say any of the good sized spot lights.
But it all depends on where the building is... Personally, I do not like any of the big portable spots with the rechargeable batteries.. they just never seem to be charged up when you need them and when you do charge them, they aren't needed.. lol I like the older kind that you'd plug into your car. but if your subject isn't close enough to where you parked, your out of luck. have you looked into any of the other stronger flash lights? there are some pretty powerful lights on the market although im not sure if their beams will be wide enough. when you do look at the different lights, try Amazon, they usually have some pretty good reviews.