Nasty Colonel Miles Quaritch, the head of security for the human mining expedition on Pandora. I based my mog off this picture (though it's not from the movie itself - it must be a pose or sets pic) but I thought the costume could use a cool weapon.
Blue Linen Vest
Rifle of the Stoic Guardian
Heh, and I put him facing that way so maybe nobody would notice he didn't have the trademark scars on the left side of his head...