I've been scratching my head about a lot of this, but in addition to building a larger skiff I want to build a purpose built river boat that I could more or less live on and also beach without tearing up the bottom.
Go aluminum for a boat you'll beach.
And make it quarter inch. Put plenty of power on it as well. Big water is no place to mess around with almost enough. There will be times.... and being able to reach deep, even if you mostly putter around, can not only be handy, it can save your life. Four-stroke is the only way to putter and still have the necessary power available if you need it.
