A few comments here. You probably DO NOT have 4-way joysticks in that cabinet. Not unless someone took a cabinet that shipped with 8-way sticks, and installed a kit that ALSO came with 8-way sticks, and yet for some reason went out and installed some 4-way sticks instead. 8-way sticks also have 4 switches, the only difference is that it can hit two of them at once for the corners.
Control panels for 19" Dynamo cabinets are easy to come by, and I think they might even still make them.
X-Arcade looks like dog poop in a cabinet, and the controls probably are not as nice as the ones you already have (if your cabinet has the sticks that came with the Final Blow kit, then they should be a couple of really nice 8-way microswitch Wico sticks with a rubber centering grommet).
If you are willing to sacrifice two player action, then you can get an 8-way, a 4-way, a six button layout and a 3" trackball on that panel without cramping. There is no way you would get a 2 player setup +4-way, +trackball on a Dynamo panel. Way too small.
You can build a bigger panel if you want too, but it will look "wrong" no matter how well it is done. 19" cabinets just didn't have oversized panels. If you aren't concerned with having it look and play like a real arcade game, then go with an X-Arcade, or go with a massive 4 foot control panel. My personal suggestion is either go with 4-way, 8-way, 6 buttons, trackball if you mostly just will be playing it yourself. If you plan on playing two player all the time, then go with a pair of 8-ways with the Oscar restrictor plates. (I doubt you could fit a trackball in with any two player setup, but you are welcome to try).