Ended up going with the Astro 6-button layout. I felt it gave me more room on the panel and I'm more than willing to get used to a slightly different scheme in the interest of comfort.
I created a Visio stecil for the 6-button layout with a Sanwa JLF joystick using the measurements from the diagram amendonz posted if anyone's interested.
Went to start cutting the control panel today and found my cordless drill's batteries are too old to try and cut holes. I got halfway through one button hole before my first battery, fresh off the charger, gave out. I'm going to have to pick up a corded drill on my way home from the office sometime this week