martin - Maybe, but it's not high on my agenda. Drawing yourself is really difficult.
nickybeats - I'm not a fan of Sacha Baron Cohen either, and I've seen a fair number of Borat caricatures, but doing him as himself might be an interesting option.
To answer your query - no, they don't all start as B&W. I'll make a decision early on whether it's going to be colour or remain B&W.
Here's a young Mickey Rourke:

and a modern Mickey Rourke:
