Most people aren't buying motor homes for there acceleration. They're designed and then buildt to move those designed specifications. Most higher powered DP are moving bigger and heavier mass. You won't find gas engines doing that for a good reason.
Most gas engines are on smaller less heavier MH's, as the weight goes up there effectiveness goes way down. A diesel engine will most likely last way longer than most gas engines in a MH, get better gas mileage, and you can actually talk to your family while traveling in your rig, compared to a gas engine MH.
With a gasser - learning other forms of communication while traveling would be Good advice.