To expand on my earlier post:
If I were getting completely ridiculous, I would say Modlite OKW or PLHv2 head if you prefer that (I'm partial to the OKW since it works fine for indoors and the throw is amazing), reptilia torch 18350 body, and arisaka momentary only tailcap. Since that ends up being a pretty expensive light, I am fine with arisaka 300 + an arisaka scout light mount for a basic carbine.
FWIW I have Modlite OKW, Cloud OWL, Arisaka 300, Arisaka 600, surefire 300 (old one), surefire x300u, and Inforce WMLx mounted on various firearms. They all function absolutely fine for moving in and around buildings, but the modlite, cloud, and arisakas are much better choices if you need to use them outside at just about any distance. The modlite wins for being able to see stuff at long distances. The Cloud OWL does a good job of that and also wins at being physically upsetting to be spotlighted with out past 100 yards.
That said I don't blame anyone for not wanting to spend hundreds of dollars on lights. For a much more budget friendly option I think the Inforce 800lumen WMLx is very nice (just don't expect to be able to see much past 50 yards with it), and supposedly there are good streamlights out there as long as you don't use the pressure pads and stick to tailcap activation. Cheaper than that, I would look for a ring mount + a Klarus or something.