Good topic idea! I like Nash Bilton or John Templeton (not as people! they're wrong 'uns) as the they give the Law Dogs a darker side that the faction otherwise lacks and are genre appropriate. I think Templeton died in the very last set, but Bilton is still with us!
Or maybe William Rose to fulfill a friend's story prize from over a decade ago! 
I'd also like a cool drifter like Montana Holland or some such to have their story explored.