Any advice for hacking a Gamecube controller to play a Oldstyle stick on the GC?

I'm planning on hacking a Gamecube controller by making it a Neo->GC adaptor. Who's hacked a GC pad before? How do I deal with multiple grounds? How would I wire up a shoulder button (since it's analogue)? Any brands of choice for hacking (with the cheezy, huge copper pads for soldering to)?

Just in case you're wondering, I'm going to use this for the Gameboy Player.

Ignoring for a moment the fact that there's already a nice stick for the GC, there's no difference between modding a GC pad and any other game pad.

1. What kind of multiple grounds are you expecting? The GC pad has only one ground circuit, like every other controller I've ever seen.

2. Have you forgotten about the switch on the analogue shoulder buttons? Use that.

3. I used a Hori pad for my adaptor (see below).

Part of the fun in making your own adaptors is discovering how to do it, and by the sound of it you haven't even cracked open your GC pad yet or you'd have noticed the switches on the shoulders. Get started, boy.

Well I heard that in a lot of gamepads (like for PC and PS2) they have multiple grounds. Will most crappy 3rd party GC pads work well for this? And plus I know I could get a stick for the 'Cube but I like a good DIY project .

My enclosure probably won't be as nice, I'll probably drill a hole in the pad and route a DB-15 cable out through it.

I don't generally buy crappy 3rd party pads, too many blown PS1 fuses in my past to ever walk that road without due consideration. Ergo I can't answer the question.

All pads are easy to solder once you've done it a few times, just remember not to flex the wire after it's attached.

I guess the best solution would be to buy a Nintendo brand controller, but a junked one; I don't want to spend much over $20 on this endeavor. I'll be in the market for one in the summer...