A lot of Police Officers use the various rechargable Streamlights. I think that is a good choice to consider.
In Hospital where I work, I saw three exterminators, and they all had Streamlight UltraStingers on their belt. (Professionally dressed also.) Rechargables are a great choice if you are using the lights every day. Pest control has come a long way since the days of a Janitor with a spray can!
Streamlights do not have the "coolness factor"and the "perfect beam" that the SureFire's do, but they also have a long history of being very reliable (chances are, if you see a uniformed Police Officer, he will probably have a Stinger or a Scorpion on his belt - of course there are the Sure Fire alternatives). I don't want to make it sound like the Streamlights are bad, not at all. My next door neighbor is a LEO for Houston PD, and works nights in a bad part of Houston, and he loves his Streamlight, and he uses it every day. The beam quality would be like comparing a Lexus to a GM car. Streamlight's beam would be the GM car and SureFire would be like the Lexus. Now the Streamlights are increadibly durable and reliable, and well made (and bright too). I do not want to imply that the quality of the light is like GM vs Lexus. They would BOTH be in the LEXUS, or BMW or Mercedes catagory!
Also consider the Princton Tec Surge It uses 8 AA batteries, and it is very bright (do searches here to read all about it) When I first joined CPF, all the rage was the Brinkmann Legend LX and the Princton Tec Surge.
Would LED lights work for you? If there is a lot of ambient daylight around, the LED's might not work, but look at the Lightwave 4000. It is a big sucker compared to the LX, but it is about the same size as a 3-D light. It has like 41 days of continuse run time. Do some research and read the reviews of this