When Steven Boehm built my M4 in 16' we went with:
Trijicon RMR (I prefer the R01 that is Nickel Boron coated for an H20+ build)
Ava Tactical Weapon Light Mount
- Surefire 500 Lumen Scout Light Head
- Surefire Outdoorsman body/tailcap
Assume the Surefire models have changed by now.
So far so good.