Just got this recommended to me on Youtube:

https://www.youtube.com/watch?v=E0hBHzCAu6o

Basically, the gun Metal Jesus tests out (by Sigin or something like that) uses a camera to detect what you're aiming at, rather than sensors or something like that.

MJ said it had some issues and he needed to tweak each individual game in MAME and at one point his ceiling lights interfered, but these problems were quickly dealt with.

I'm not quite ready to take the plunge myself but considering my own woes with having lost my CRT television, its nice to know that I have an option for getting back into light gun games should I feel up to it.