I am researching Class A Diesel motorhomes for a purchase. I have spent numerous hours on the net looking at different models, at dealers lots looking over, inside and out, different models and have come to the conclusion that it doesn't matter what you buy you will have what you pay for. So my questions come down to this: looking at all the motorhomes I see CAT, Cummings, etc., diesel engines from 245, 265, 275, 300, 500 hp. For a diesel pusher that is say over 34 feet long with say 2 slides which size engine would you recommend? The driving area would be the total USA. Thanks.