Thermal for spotting and shooting, Night Vision for navigation.
Edit: my experience is military (old tech) and recent using high end setups doing run and gun at night at competitions with borrowed gear. But shooting is way better with thermal, and running through the woods is way better with NV. Shooting with just NV requires optics be setup at a height that works, with magnifiers etc if using NV compatible red dot settings
NV need an illuminator?
Depends on the setup. Using the really high end stuff I could make hits to 300ish without, but I'm not buying double tube nods, helmet, mount, 1.9" optic mounts, etc for 10k+ to shoot with NV, and using and illuminator literally screams HERE I AM to anyone using NV in the area. I mean, a great illuminator is amazing, but it's like a tracer at night times a billion. So it really depends on your intended use. I'll probably go thermal with a unit good enough to work as a decent scanner, but I don't plan on running around in the woods at night playing Ranger/SEAL/Recon, so intended use would be detection and shooting.
