Wildclay-
On the single color LEDs, I soldered the ground to one side and the power lead to the opposite side. The other corners have pads as well, and I discovered that if I soldered lines to those two and spliced them to the power, I could triple the brightness, so I did that. I'd post a picture, but I'm at work. It works well, though.
On the machines I am using my RGB buttons, I am using an GP+LED-Wiz. Since this machine just has one joystick and only 4 buttons, the GP+LED-Wiz worked perfectly. On the cab that is going to have the 12 lit Red and Blue buttons, I am currently using a LED-Wiz. Since I am just lighting single color buttons, this also works perfectly. In fact, it currently is lighting red and blue buttons, but I don't like the shape. I prefer the tradition Happ/IL pushbutton, so that's why I'm going IL translucents all around. Oh, I also have a Ultimarc Pac-LED put aside for a project, but I haven't used it yet. It's the older style, not the 64 port one. If I were to get the PacLED64, I'd probably just buy everything, buttons included, from Ultimarc since they seem to be made to connect effortlessly.
For a good tutorial on lighting and wiring, check out my homie Nephasth's Two-Headed Beast build, starting with
this post as well as
this one. I learned a lot from it and used it in both builds. After I wired the LEDs the other night, I drilled holes in my buttons and ran the wires through.