What you propose is almost identical to what Roadtrek/Hymer offers on various models. Perhaps taking a look at what equipment they are selecting may be helpful.
The main difference is that Roadtreks/Hymers I've seen did not have a generator, and therefore can't charge batteries from generator -- although that's minor difference because they can charge from shore line feeding inverter/charger. They also had solar that charged lithium batteries.
__________________
|