You can always design them yourself. They aren't very difficult to do.
Basically you need a cad package capable of printing 1:1. I use AutoCad 2002 Professional or AutoCad v14.
Basically draw your control panel to scale - basically just a rectangle.
Second, using the dimensions from the pushbutton / joystick's manufacturers, make little 1:1 pushbuttons.
Basically only the cut-out and a center mark for the cut-out is necessary, but you should put the pushbutton in there as well so you can get an idea of what the actual size is when arranging your buttons etc...
Thirdly, if you have any wood pieces or other parts underneath your control panel (such as my TAITO panel), make sure you mark "keep-out" zones on your panel outline so you don't place buttons there.
Next, decide how many buttons you want to use, and then just plop them down and arrange them how you like.
When you are finished, you can just print out plots of your control panel at 1:1 scale and mark your control panel for machining from there.
Very easy and very accurate.
AutoCad also lets you import graphics files (such as control overlays) so you can see exactly how your panel will look beforehand.
Perhaps if other people have access to AutoCad, we could start making standard arcade buttons / joystick cad symbols to use for this type of control template design process.