You might even ask Simon at Convoy how much to throw together something like what you want. He’s generally pretty flexible and can custom-tailor a light to what you want. He’s wonderful.
A green S2+ with shorty tube would be quite fitting.
Just ask if he has a green emitter to stick in there, and a driver that doesn’t push it too hard (even 2×7135 should be plenty at night). An older driver without the horrendous blink-on-low, ie, an older NANJG driver with the stars on ’em, can be configged to something like 3 steps of l/m/h.