Hmm, not that I know of. But: I use a CST ltracx in my left hand, and a razer abyssus in my right hand. this is because the abyssus is great for games, and the ltracx is great for everything else. also; left hand mousing is more ergonomic(at least it helped solving my problems.)
I know that this probably wasn't the answer you was looking for, especially considering the fact that it exists few left handed thumb trackballs, but it's just a suggestion.