Any of them will work, it’s more what you can get ahold of cheap. I prefer to avoid ammonium nitrate personally. Not a fan of the smell more than anything.

Ftn is going to be the most effective long term solution. Plaboi was an absolute genius with his designs. Especially if you print with reinforced nylon and use cf or aluminum tubing for reinforcement

Cci quiets will do the trick. Were you running subsonic 22lr? 950 is awful fast for a subsonic 22lr.

I feel like crimping a jst sm on the ends of the thermistor wire and doing a loop with normal wire to each and putting the resistor on that with heat shrink is probably a more sturdy solution long term. You have more than enough room inside the front faceplate to make it work. I used jst sm on all my hotend connections on my 500c ender with zero issues. And that’s fans, crtouch, heater and pt1000. So no worries about it melting a connector as long as it doesn’t touch the nozzle.