I have collected a bunch of the various superguns made in Japan through the years, and overall I like the Sigma control boxes the most. I think those modular units are a bit more versatile than the ones w/built in controls, which take up more space. When I got my first PCB back in 2004, the supergun that I used was the Sigma AV7000 along with its proprietary controller, the Hexa 9000TB stick. It is made by a company that manufactured Pachinko machines and arcade cabinets in Japan, so the build quality is top of the line. Definitely recommended.
Performance-wise it is very dependable, since the AV7000 is little more than an arcade PSU with attached connectors for a JAMMA harness, A/V + controller ports all enclosed in a tidy metal case. No moving parts besides switches and dials, so it'll last a lifetime with proper care. The controller is also very sturdy, with nearly all metal construction and using standard arcade parts by Seimitsu (LS-32 joystick & PS-14-G pushbuttons). Setup is quite simple too, as there is little to adjust and everything is clearly labelled. Just plug everything in & play.
I haven't had issues operating any of the games that I own. I've played a wide variety of hardware with it, ranging from huge multi-layer '80s PCBs to systems like Atomiswave, MVS, CPS2, F3, G-NET & PGM. It's even capable of running a Naomi 2 GD-ROM & DIMM setup through a Capcom I/O interface, after adjusting the voltage a bit. An important thing to note is that I've always used 15 kHz compatible RGB CRTs for the display. One of the more common issues I've read about regarding superguns involves the video signal and getting them to work with upscaler devices. Something to consider before making any purchases.
A couple of useful videos:
https://youtu.be/XNsfASK-ifkhttps://youtu.be/_RUVeQ7fgjUThread about numerous models of superguns:
https://forum.arcadeotaku.com/viewtopic.php?t=19661A shop that carries most of the currently available superguns in Japan:
https://www.tops-game.jp/products/list. ... egory_id=1