I like Logan (go berserkers!

) just fine, but Major West was my favorite :P Just because of the very well done character development.
Abercrombie has more books in First Law world so if you haven't read Heroes, Best Served Cold and Red Country. Heroes features a character from the First Law trilogy, namely Black Dow.
There's also a First Law comic which you can read for free if you're craving for more Logan :P
http://www.firstlawcomic.com/archive/1/
As far as the sequel to First Law trilogy goes, I know he planned it, but not before he finishes his YA trilogy.
Maybe you can find more on his blog.