Reaux,
You can fly under the NVFR during a commercial op in a single. The only restriction is that it can not be passenger carrying. So that means that if you are empty or carring frieght only you can fly at night.
Something that I also didnt find out until I was up north is that your NVFR rating can be for a single or multi eng aircraft. So if you did your NVFR in a single, then you can not fly a twin under the NVFR. A way around this is if you have CIR you can fly a twin (day or night) provided you operate under the IFR.
LemeL