Nice build, I was playing around with fire skills too. This build with Cindercoat+Magefist+Andariels Visage is a killer. Also if you lack discipline use Night Stalker instead of Seady Aim. You can keep shooting everything down as long as you crit you get discipline back.
You probably don't want to use Andarial's. That causes you additional fire damage (unless you roll +fire as well on it but there are probably better helmet choices). I'm using Cindercoat+Magefist+Custerian+socketed Hellrack for some serious fire damage. Grenades hitting for around 2mil with cluster arrow crits for 10mil. If I stay away from packs, because of pridefall+magefist+cindercoat I can use cluster arrow 7-10 times in a row before I run out of hatred. I've been using a wolf but may try the bat to see how much the hatred regen helps. This guy is still a work in progress, been spending the past week on tweaking.