First you need to know the difference between
digital night vision binoculars (monocular) and
thermal imaging scope (sight),qaultiy and price gap.
Then you need a compact lightweight and multifunctional one, Trieagle 2302 Q35 Q50 Q75 series is the right choice for you.
As for thermal imaging device, you need to know the detector resolution 384X288,or higher range 640X512 which has features of high sensitivity,high refresh rate,high stability.
Muliti functional features makes it better choices: support in screen shot, cursor,video recording,warm spot tracking, but wifi none.