I'm going to go with the Rockville RPA12 (https://www.amazon.com/Rockville-1400w-Channel-Amplifier-RPA12/dp/B07NZZW7PX/). They're general purpose power amps so you can run a pair of speakers or a single subwoofer. You'll need 3 - one for each pair of cabinets you're running. You'll run the subs in series for a nominal load of 4 ohms. $900 total cost. They will run off a 10,000w generator.