I've seen someone use a modern M14 with all the RAS, Crane stock etc and a combi torch and red laser unit... at a CQB venue! Bloke called Coldy - he did really well with it too.
If you search fleabay for Ultrafire XML T6 you'll come across a range of excellent options. The type with 2 18650 batteries and the zoomable bevel are probably best as weapon mount torches, but they do not come with mouse tail pads; you can mount them so that you can press the switch with your thumb without moving your hand off a vertical foregrip. I've just ordered a pressure pad which may fit:
this. The single battery one is also good, just not mental bright, but obviously lighter.
There is also a torch model "C8" which uses the same Cree XML T6 LED and they come with a mouse tail; it uses 1 18650 but produces a bit more light due to a bigger reflector, but the glass may well break if shot - I have used one with a couple of layers of blister pack clear plastic covering the front of the bevel and although BB's went through that, they didnt break the glass. The C8 often comes bundled with one or more 20mm mounts and barrel mounts.
These 3 types all come with 5 modes: full power, 1/2 power, low power, strobe & SOS. The prices of them go up and down but you should be able to get any of them for around £10
I'm planning to get an 9500lm Skyray soon, possibly on Tuesday, for around £25 - these come with 3 modes: Full power, Low power and Strobe (gulp!) but afaik there is no 50mm diameter circular mount that attaches to a 20mm rail so i will need to cable tie it on. The short stocky type uses 4 x 18650's and 7 XML T6 LED's, but there are some which use 2 or 3 18650's, utilising an extender tube and 3 LED's with 5 modes, and these fit into 30mm mounts with a spacer, so even though they put out around 1/3rd as much light, they may be more useful.
I dunno... I mean really, an 9 1/2 thousand lumen torch is probably pointless overkill, but i just really fancy seeing how disorienting so much power in a strobe can be :lol: