Not cheep, but worth it - Streamlight ProTac Rail Mount HL-X Pro Long Range 1000 Lumens Gun Light w/Remote Switch

Streamlight products, or atleast the ones ive bought, are very robust and durable. Worth the extra 80 bucks over just as bright nockoffs. The focus and flood on the lense is good enough for scanning and full illumination around 120 yards, and will reach out farther. So far very pleased. Came with zipties also, not a massive or expensive thing, but very nice to just come on hand, given you will need them sooner or later. Overall, very worth as always with streamlight