You have a generator to use while you run for parts.
I would call it what it is not try to duplicate everything just in case.
Many solar controllers can charge 12, 24 or 48 volt batteries. Inverter and batteries I think you would be better served with duplicate systems over swapping from 12 to 48 volts and back.
48-12 DC/DC converter is easy to run accessories.
I would be skeptical of the reliability of a random China 12-3000 inverter unless max draw is 1500 watts. I recommend GoPower, Magnum or Victron inverter. Over 2000 watts I would go up in voltage.
