I've already done the research, found a number of sites that have the PCB wiring. Including the one you linked. That one is wonderful - it has a LOT of PCB wire schemes, though. I bookmarked it within thirty seconds of opening it up. =)
And actually, I'm probably going to be using all three - PS2, GCN, and 360 PCBs in it. If I buy controllers on eBay, I can get all three - a wired 360, a PS2, and a GCN (all brand-new) for less than $35.
Doing a PS2 controller is apparently ENORMOUSLY easy - rather than soldering to the various points on the PCB, you just insert the wires into the appropriate slots on the PCB's connector. LOVE IT.
I think I will house each PCB inside the box, but have them run to a connector attached to the outside (so, there'll be three female connectors on the outside). Then, the controller buttons themselves will be wired to a male connector that I can swap from each female as I please. This keeps each one separately wired - never crossing each other, and never worrying about having to have power to each one to keep it from frying. Kinda complicated, but it'll work better than anything else. I may have the actual connectors hidden behind a small door on the outside so I can keep the entire thing nice and aesthetic.
I also found these pages that are useful in building a custom arcade stick:
HarumaN's Xbox 360 Controller Hack Tutorial
X360 custom controller build (excludes LT & RT)
RDC's Complete Controller Wiring Hack (INCLUDES fairly simple instructions for LT/RT)
Project Gyokusho
SW-5120-1900-6153
