Not all used. X-Gaming manufactures their own for their cabinets as an upgrade option. They are expensive though. I didn't look for the monitor, It came with the system. It's a 32" CRT. I think the largest PC CRT monitor was 21 or 22". After that they went to LED.You talked me into the track ball.
It's awesome you have a real CRT. I don't think it's an option for me but I'd love to be able to do that for authenticity and it solves the light gun issue! Is it difficult to find a CRT monitor these days? Are they all used?