Have you ever heard of the Bliss Box project? This guy developed a USB interface to connect original console controllers and peripherals to PC, which utilizes custom cables with connector types for all the old consoles. I got hooked up with him a long time ago on the Underground Gamer torrent community (when it was still a thing, RIP). I bought the original version of the Bliss Box PCB years ago, then after that the 4-play, which I'm not sure you can get anymore, but as far as connecting "old school" controllers to PC for emulators, it's awesome. I've never used it with an original Nintendo or Sony light gun, but I happen to have a CRT TV of my own so I can test it out and report back. If it works, since you have a video card with TV out, it should work for what you want, if your goal is to use original light guns with modern emulators.
Other than that, Act Labs used to make legit light guns for PC, but they've been discontinued for some time. They pop up on eBay from time to time, but of course you're going to pay a "rare and desirable item" premium. I have a couple of those and they work great with MAME and my CRT arcade monitor. I tested virtua cop, it's just like the arcade. I would assume (and hope) the Bliss Box would allow the same experience for console emulators. Since the Act Labs guns are for PC specifically, they should also work.