I loved lightgun games on the old systems, and I think the Sega Saturn’s Stunner was the best hardware of the lot. The obsolescence of CRTs pretty much killed the tech, but the gameplay style has made a bit of a resurgence a couple times with the advent of the Wii and VR.
There’s a gun available called The sinden lightgun it doesn’t use infra red, it had a high speed camera in the barrel and monitors it’s position relative to the border of the TV. Works brilliantly on modern tvs and even projectors.
There’s also the GUN4IR project that can be put together for a fraction of the cost of the Sinden. The Sinden requires a visible border around your game.
I second the Sinden. I use it in MAME and it requires some config changes to set it up, but their support documentation on how to get it up and running is spot on. The only real problem game I’ve run across is Terminator 2.