Without a budget number it's not easy to make recommendations.
Finding all that seems unlikely in one unit.
I'm thinking a Foretravel below your price range then take it the factory for updating.
They are good at updating and making custom improvements. They all have side radiators and a retarder in the Allison.
They are quality units, they use quality components and because they are monocoque, they are at least one step, maybe two steps lower than many DPs so easier for your wife.
Look at MOTORHOMES of Texas.