Lighting exterior at night

Hi

I am currently planning to shoot a student short film. I will be shooting a hostage scene outside in a field, this scene takes place at night, however I have never shot a scene outside at night. I am shooting with a Panasonic AG-HMC154ER(AVCCAM). I will be using 3 2k Blondes, 3 800w redheads, and a 2.5k HMI. I would like to get some advice on how best to utilise my limited lights and whether it would be better to shoot the scene at dusk in order to get more light, and then bringing down the exposure in post? The look I'm going for is very film noir-ish, with very harsh shadows and a 1:6 - 1:8 tonal ratio. Any input will be much appreciated!

Thanks
Simeon