Hello, one of the maxuino guys here. I know that Firmata will allow you to use any digital pin to do servo control, and so in theory you could use an arduino mega with firmata and maxuino to control all of your servos...in theory. I have heard some reports that there is a point where firmata and the arduino just cannot manage all the various simultaneous pwms needed for more than 6-10 servos...but i haven't tried it for myself. As to the power supply, use your multimeter and check what amperage the red or black wire is pulling when you turn the servo (remember the multimeter has to be in line of the circuit to do this test, not just touching two places like you can test for voltage) and then multiply. I would guess you would need at least 5-10amps for that many servos...pure guess tho.
look forward to hearing how you make out.
Chris