I'm working on a 2 player cabinet. I already have an Ipac-2, OptiPac, 1 Mag-stick Plus, 1 UltraStick 360, and several buttons. I still need to buy a spinner and track ball, but I am feeling overwhelmed by all the choices and I'm a little unsure as to what will be compatible with my OptiPac that I already own. Also, I'd like to be able to use the track ball as a mouse. Can someone please point me in a good direction? The U-track seems nice (a little pricey tho). I have also looked at the Groovy-TB, but I can't tell how hard it would be to hook up to the OptiPac. As for the spinner, I've been looking at the Spintrack from Ultimarc and the TurboTwist 2. Advice???