Mantorok

I realize that this is not a cabinet-building site per se but everyone seems very friendly! I am trying to put together a cab for personal use, as I happen to have two "good enough" PCs that aren't being used. I plan to use GameEx as the front-end, since I mostly will be using NES and such, rather than just MAME. Right now I am still looking at the options. I plan for two sticks +8-10 buttons each, and also a trackball plus some buttons. I get the impression that most builders use the trackball to control the mouse in GameEx? It seems intuitive, if it somewhat reduces the magic (sure you can control with the stick and buttons but it seems a little complicated... comments?). Everyone seems to buy from Ultimarc, and I assume I need a i-pac to control the two players, plus buttons and the stick. Is this the bare minimum that I need, if I am using a dedicated motherboard and computer monitor? I'm basically broke. The thing that I'm not sure about is the trackball, a second controller is required for it? Between the OptiPac and the trackball that is like 80 dollars. Am I missing something? Is there a more affordable combined controller somewhere? Wouldn't it be easier to just buy a Logitech trackball or something? Obviously that would be tacky but I don't see how a $60 difference makes sense. Thanks for any clarification you fellows can provide!