Relentless: I don't have the complete answer on the Granite floors, just a caution. We had ours done in Granite a couple of years ago by a house installer. He had no knowledge of the flexing our coaches take. Hence some hairline cracks in the bathroom. I know now it takes a flexible underlaymet to make it work. Check around until you find the right proceedure. We love the way it turned out other than that flex problem. Granite is a lot more scratch resistant than Marble and a better choice. Good Luck on the new Coach and welcome the Asylum of POGers.
Harry