In tank pump will run cooler and more efficient, should be a bit quieter everything else being equal. If you run an external pump you really should pull from the bottom of the tank and not the top, less than ideal in a rear mounted fuel tank in an off road vehicle. Inline pumps want to be gravity fed.What is the advantage of putting an inline fuel pump inside the tank as per the above picture? Noise? Definitly looks official!
IMHO and inline external pump could be more prone to problems and has no advantage the way Rush will be using it, buy a quality fuel pump put it your tank and forget about it.
only thing I would do different is I would add an adjustable fuel regulator and return line if I was building his system.