That's a lot of load for one alternator, but with proper batteries it will work. Watch the voltage and if it starts to drop too far after playing a while pick up the engine speed(if idling) and lay off the system for a couple minutes to let the batteries recover.
I have seen people do more wattage with less alternator so I think you will be fine.
If you need more power we do have our new hybrid that's going into production shortly that has done [email protected]
in my Crown Vic Police Interceptor and is now being built to fit GM too.