Ceili has the right ideas with this...
Some of the other images wouldn't work as silhouettes because, for example, if you have an arm crossing into the body's surface, such as in this one....
then the arms would disappear and it would look a bit funky. It would work ok if you cut the outline and then paint the figures, which I might do with particular design because I like the way it looks.
This one by Beth might work quite well...
It has nice simple lines and should stand on its own, but again, if it doesn't it would be quite simple to paint it.
I'll continue looking. When I find the exact image I'm looking for, I'll post it.
(maybe I'll have to toss in some weird stuff just to keep Sozobe guessing)