the Estes Pro Controller is different from the Porta Pad II, this one can hook up to an external 12V *car* battery to fire any igniter on the market, as opposed to the 6V (4x1.5AA) source from the porta pad. Personally, I would not go with the Aerotech system. It is expensive, and unless you cut off the the igniter clip, is unusable for any other type of igniter except for the Copperhead-type.
Or, you could go even cheaper, and go down to your local hardware store and pick out two switches, one that turns off after you release it, buy some wire, connect it all together with a battery, and you have a cheap controller.