First, suggest you get a datasheet. Got a hunch you aren't familar with the raw sensors. You need a bunch of other support to use them, but fortunately you can get most of that on a single chip.
I've got a similar project in the works, but for scaring off the neighbor's cats. I've got two modules from Futurlec, $6.90 each.
https://www.futurlec.com/PIR_Sensors.shtml
I could be wrong, but get the impression that if the sensor is moving, you'll get a lot of false readings. So mine are stationary, a servo motor will sweep right or left while the gun fires. Was all set to stuff the gun in a piece of 4" PVC, but couldn't cut it down small enough. Guessing I'll need to cut a big hole in the side of the PVC, or find some bigger pipe.
Find and read the datasheet for your sensors, as you will need to know what kind of signal to expect, timing, pinout, and power requirements. Sounds worse then it probably is. My modules are tiny, and not a lot of parts. You'll need to find out which chip will work best, but you probably want your own circuit for what you want to do. The modules I have need 5 seconds between triggering.