imo the rocket or at least the roadster model is not a cruiser (though it does everything a cruiser does only better) and its not a sportbike or sport tourer, but a naked musclebike, so the fairing should be a minimalistic type one. like the bits on a benelli tnt.
if i was to have a fairing built and i probably will some day, id start with what is already available and looks good, and build from it. we have a sportscreen (angry roundy one like perdurabos, also seen on carbondryjapan), chin spoiler (chris in UK makes them) and trims on the radiator.
i'd take the angry sports screen and make it a bit wider and have it come down around the sides of the lights.
i'd take the chin spoiler and extend it to make a belly pan/chinspoiler, and have the belly pan come up around the sides a bit to guide the wind off your feet/pegs.
i;d take the rad trims and replace them with a chunkier version that splits the air to either go into the rad or out wide past the knees. and it should compliment or almost link in with the screen above and the chin spoiler/bellypan below.
i spend a lot of time fantasising about this stuff