The Xtension is shit, and it looks like it too, avoid it.
Building your own control panel is easy. Once you do it you'll wonder why you ever considered a crappy off the shelf controller that looks stupid sitting in a cab.
But this is a pinball forum and the resources here are limited. Get over to a place that's actually full of super helpful information. You can start here:
http://arcadecontrols.com/arcade.htm
But go to the forums too. Trust me, you'll find anything you want to know there.