All these thermals you are thinking about will get the job done. But also keep in mind aspects other than "best image". For one thing, "best image" is not strictly a linear beast. All thermals degrade considerably as thermal conditions worsen. Mostly "water in the air" degrades the image. And like in "heavy mist" you are looking at the critters, which still stand out, in a sea of grey and may not be able to see any terrain beyond 80 yards. This also happens during or after a lot of rain or during or after icing conditions, etc.
Re-stated the "good image" thermals, like the oasys cores, are real good in good conditions, but no better than average to poor thermals in poor conditions. I've never had a thermal that could see terrain beyond about 80yds in heavy mist. Whether it cost $3k or over $10k. Whether it was 100mm or 10mm.
But there are other aspects such as support, that are important. I had solid experience with Armasight CS before the merger, none after. I got worried and sold my three Armasight thermals. That has nothing to do with the quality of the units, just fear, uncertainty and doubt about whether I can get them fixed if they break.
IRD/TEO CS have been great for me. Last time i sent my mk3 in, they sent me back a new unit. I've never sent in a pulsar.
And some people place more importance on warranty than others. So figure out where you stand on that. This would come into play more if you went down the used thermal route.
Ergo nomics, changing batteries, DVR, etc. The TEOs are weak in the visual capability, the armasights were strong. I have done very little video with the pulsars and never got it to work with the TEOs. I did a lot with the armasights. The TEO batteries last a whole night (12 hours) for me. I do use usb packs for helmet mounted thermals. The Trails are trying hard to improve the dvr and battery aspects.
In theory the pulsars have some integrated range finder units. I've never been able to get one. But those could help determine distances quickly, which might be useful depending on the cartridge and the terrain.