Hey, TF... just curious - are you planning to make this for general computer use, or ? What are you using to drive the electronics?
I've had two panels in mind for years, though I've only "finished" one of them. The first was essentially a Slik Stik Classic clone, Happ American parts, with a Competition Pro 8-way, convex buttons (for that classic original arcade feel), a Namco Pacman 4-way stick, USP Happ 3.5" trackball w/ buttons doubling as a mouse, arcade spinner, and external controller ports (hence the I-PAC4 for what is really just a 2-way panel). I have all the parts, I just haven't built it yet. The second was a single-player fightstick. I ended up finding a MAS Systems stick on the cheap ($40 shipped). It was one of the ones produced circa 1999/2000 as it supported Dreamcast and PS1/2 (via pad-hack, and not a common-ground pad either! - and it still worked perfectly). I ended up gutting the electronics, replacing the cherry switches with new ones (going to clean the solder off the old switches and reuse later), then I wired up several items from Toodles's godlikecontrols.com, including an MC Cthulu, Imp v2, X-Box 360 Brawlpad, and (soon) a PiiWii. Wired it all up to an 8-pin din, then soldered up my system connection wires... essentially, I've now an arcade stick that works on the computer/ps3/360 and almost every other console system out there (though tbh, I've yet to solder up any other wires outside of my USB one as of yet!)
I know that this is a bit OT from your original post - I'm just still excited about it. It's the first stick mod that I've ever attempted, and I was quite excited to discover that I actually wired it perfectly the first time and everything just worked! (I only just finished the wiring last Saturday, and yes, I fully realize that this will NEVER happen again - laugh)
FWIW, I'd love to see pix of your panel externals and internals when you complete. If you're interested in seeing mine, I'd be glad to post a few pics. Good luck, and have fun!