i say, if you dont think you want a trackball, then don't bother. i didn't have a trackball in my panel for a long time, until a friend showed me centipede after we built his panel..then i had to have one. so i added it later. my point is, that unless you are really awesome, you will probably not make your panel perfect the first time. i have had so many revisions to my control panel, that i lost count. make the panel the way you want, and try it for a while. you can always make a new one later....or even a second cabinet. i had a 2 player setup with two u360s and a trackball, now i have two cabinets... a 4player panel with only 8way joysticks and buttons, and a second cabinet with a vertical monitor, tracbkall and 4 way stick.