superguns are as hard or easy to make as you want them to be,
I still haven't put together a nice one, when I first made one all I had was a computer PSU, an old jamma harness, a 3" speaker and luckily an old amiga monitor with rgb inputs.
for the controls I bought some parts from happ and folded the top flap of a pizza box in half and used a pencil to punch holes that the buttons and joystick screwed into.
Not to freak you out, but from so much experimentation I slowly hurt and damaged my first prized jamma board, I think the computer PSU's I used may have been a bit too high on some voltages, I'm not sure.
It's definitely good to have a pcb around to test with, but maybe you should consider getting a cheap game along with strikers, and cheap I mean 10$ or less (like double dragon or bad dudes vs dragon ninja or something), I had a mk2 board I tested with, but I still managed to damage a 220$ game I had been trying to get forever.... (this was like 6 years ago)