There is really nothing quick about what you want to do. I have my I-pac in the center. I ran wires from the terminal block to the i-pac for each player. First wire is ground, then R, L, U, D, etc. I do this for each player. I then daisy chain the grounds on each controller to the ground on the terminal block. If you wanted to "pop-off" your CP top and to add new controls, simply unscrew 10 or so wires from the terminal block (the one's coming from the controllers - not going to the i-pac). This will take about 10 minutes. Place your new already wired up CP on the CP box, re-wire into the terminal blocks. Tada, new CP setup. Unless you had some sort of harness where you could quickly unplug and reattach, then it would be fast.
If you want it to be fast, you could use spare molex connectors. You will need a few male and female molex connectors. Snip the wires and strip the ends. If you have a Joystick, 1Player Button, and 6 buttons, you will need 11 leads. Three molex connectors will give you twelve leads. The problem with this setup is the color may trip you up since molex usually uses a yellow, black, black, red coloring scheme. If you were to wire up all your CPs like this, it would save a lot of time instead of unscrewing everytime you wanted to put a new CP on.