Have not read the whole thread...
Couple of points:
Watts are watts... does not matter what voltage... watts are a measure of power.
Basic formula (Ohnm's law): V x A = W (volts times amps equals watts)
So 12 volts x 10 amps = 120 watts...
And 120 volts x 1 amp = 120 watts...
Make sense... grin
Remember to never load a gasoline generator above about 80% of rated 'continuous' output, regardless of surge capability.
And always mix "StaBil" in the gas can for the generator (I prefer to have a separate can for this)... and always change the gas at least 2x per year and run it for a while to be sure the carb stays clean. Otherwise... it WILL NOT start when you need it...
The watt-hours thingy is how much power you will need... in watts...
That is the key.
You can always 'load share'...
That means turn off one thing, while another is working...
Example: turn off the fridge while making your coffee or mirco-waving your frozen food...
If it were me... I would go heavy on the storage batteries... the less you take them down really low... the longer they will last. Golf cart batteries are designed to discharge and re-charge... probably a good compromise between quality and cost.
Your inverter needs to be rated for more power than you plan to use also...
Harbor Freight has some inverters cheap... might look at those.
The sales guy at the local HF store... said the truck drivers buy them and use them on the trucks running over the road... power a TV, elec heater, coffee pot, microwave, etc...
BIG trucks have 200-250A alternators... some are 24V
Hope this helps...
Grin