As Cornelius has pointed out, a typical charger simply does not have the current you need, but other options exist. eBay is a good source of power supplies. You can get what you need for ~ $20 (US). Also note that, depending on what's available in the way of power supplies, you can connect your elements in combinations of serial/parallel, to use either 12 volts/16 amps, 24 volts/8 amps, or 48 volts/4 amps. I'm ignoring the fan loads here, although I would strongly recommend a fan per element, total 4 rather than the 2 you have specified.
That said, you may not be able to drive your elements with a full 12 volts. Unless you have a proper heatsink on your cooler, with proper airflow, the Peltier will overheat and may self-destruct. So make sure you have a temperature sensor on the hot side of your elements, with the circuitry to cut off your power supply if the element gets too hot.