I got lucky and found these 2 boxes that are very heavy duty. Taped together, they should support the weight of the monitor. The height is about 3′ so it will make a good base for the cabinet. Overall, your cabinet should be about 6′ tall for the “authentic” feel.
Keep taping boxes onto the base to fit the approximate dimensions of an arcade machine. There’s no measuring required, just do what feels right. Make sure to include a shelf area for the control panel.
Cut a big hole in your monitor box (see above picture) and some small holes for the wires to go through.
Here’s a nice spot for the speakers and sub-woofer.
It would be nice to conceal the PC inside, but in this case I didn’t want to ruin the support structure of the base boxes. I taped a scrap of cardboard to PC case so it would fit with the overall visual style.
The box I used for a shelf became a nice keyboard & trackball drawer once I cut it open.