Isn't Illustrator great? The thingy in the center is how I do the symbol most of the time, I have some versions of it by hand that I have to get around to resizing because it scanned at a waaaay too high res.
Like the sketch, but you should concentrate a bit more on blending the photos with the sketches and renders. Maybe a slight gaussian blur? Don't get me wrong, you've got some fun shit here, just a friendly suggestion.