For anyone interested:
Progress on the picture (original post) hasn't been as fast as previously hoped. I've done sketches of a whole bunch of you guys, but the bottleneck is in digitizing them: my method has been to scan the image and digitally trace and colour it. I don't own a tablet, so this step has to be done via mouse, which is far from ideal. But it's what I did with the last one, so the end result isn't too bad.
I've digitized about 5 people so far and progress is continuing, albeit slowly. Feel free to make more suggestions. :)