0K. First of all, even if you care to use a warm high CRI emitter like a 3000K CRI80+ XM-L2 or 2700K/4000K CRI95 SST-20, you should get more or less 300+ lumens out the front of the flashlight with a TIR lens if the emitter is driven at 1.4 - 1.5 A (check some emitter reviews like Test of a Luminus SST-20-W 3000K 95CRI led -djozz- or Luminus SST-20-W 4000 K CRI95 color and output test -maukka- if you like). I'm already counting some optic and heat losses, but my figure should be close enough. The TIR lenses will provide you with a nice blanket of light (no hotspot at all), so no one will think you're "sniping" something unless you straight focus at it leaving it in the center of your beam. My close up work flashlight has a 30° TIR, and to my eyes it covers a 60° angle (the figure is a half angle metric). So ask Simon to bundle you at least 2 or 3 lenses (10°, 25° and 45°), or just order a "1pcs per degree" 5-pack (10°, 25°, 45°, 60° and :???: strip lens), that way you'll be able to test by yourself which ones you like better. A lens with a wider angle will spread out the light more, making the beam less intense and you may have to get closer, but at the same time you'll cover a wider area and be able to peek more items stealthily.
As I said above, you can get the SST-40 driver which goes up to 5 A or some Biscotti 8x 7135 driver both of which, in medium mode, will provide you with decent light. The SST-40 driver will give you almost 1.5 A in medium -30%-, while an 8x 7135 in medium mode will be somewhat below depending on the chosen mode group, so it'll be less bright. With 1.5 A at the emitter, a 3000+ mAh cell and a low Vf emitter, you'll at least have 2 hours of non-stop runtime, a little bit more in practice depending on the cell you use. Don't worry with the temperature thing, 1.5 A max means 5 - 6 W of burnt power at the flashlight, it doesn't gets too hot at that power (and anyway, the SST-40 driver has temperature control). I once used my nephew's S2+ with a headband to go jogging (40+ minutes, an after repair test) at night, and it performed wonderfully without getting toasted.
Runtime speaking you can switch modes to save power, and/or take more batteries with you if needed; it's a pretty quick swap.