These amps require 20-30 amps at 12-14.5VDC to operate at rated power. I use a car battery [at my bench for test] and charge that with a 14-15vdc 1amp wall wart or solar-panel. This is far cheaper than buying a clean !2V 30 amp power supply. You can opt for a smaller gel-cel but it may not last as long.
It is also interesting to note, if you do the math given their specs, 12v @ 25 A= 300watts, not 1000W. The 1000W label suggests output "music-power" but is really dissipative or HEAT power. So these amplifiers are really125-150W RMS real power output, for your reference.
The rule of thumb in amplifiers is $1 per watt. If a "500W" amp costs $99 it is really 100W amp in terms of music output power. The rest is dissipated as heat.