I've never tried this (I've thought about it), but I think that it's just too many things to get onto one panel at one time. I think that no matter how you lay it out, you're going to have one of two problems: Either some controls will be too far off center, or too close together to use well.
For instance, if the trackball is to the right and well out of the way, you're either holding your hand way off to the right (which is going to feel odd to anyone not used to it), OR you are standing by the trackball and seeing the monitor at an angle.
On the other hand, if you crowd the controls close together at the center, you're going to have interference between them when trying to use them (and probably when trying to mount them!).
You could try vertical alignment of the controls in the center of the CP (joystick near the monitor, then trackball, then spinner), but I think you're still going to get in your own way, and the control nearest the monitor is likely to feel funny because it's so far away from the user.
If I were you, I'd pick 2 types of control (perhaps the stick and the spinner?), and set the controls left and right of center on the CP, with buttons out to the sides. I REALLY think you'll be happier that way, than if you try to cram all 3 on there.
For my own purposes, I'm planning to go with one type of control per cabinet - first up is a cocktail with 2 trackballs (it's a missle command cab) that I'll just put every trackball game I can find on. Once that's done, I'll figure out what's next.