Hi all. First post here...
I recently discovered this site, and after browsing through lots of other controllers people have built, I am strongly considering building my own (I originally thought about getting an X-Arcade, but I guess it's more fun to do it yourself).
I mainly want a 2-player controller for the various Capcom fighting games. Here's my current design:

The only thing I'm debating about is the 3 purple buttons in the middle. I want to make it "lefty friendly" and am wondering the best way to go about that. My main question is how do lefties play? Would the buttons layout be mirrored compared to having the buttons on the right (i.e. button 1-3 go from right to left)? Or do the buttons go in the same direction (from left to right)?
Should I put an additional 3 buttons (so there are 6 buttons on the left) and simply wire them so they are clones of the buttons on the right?
I'm also wondering about what material might be best to build this out of. Weight isn't a big factor (ideally I want it to be a bit heavy to keep from moving during frenzied gaming).
Also, what's the clearance needed for standard horizontal microswitch buttons? Would 3 inches be enough?