Glad you're enjoying the build. :)
Looking at your profile, it looks like you're off to a good start, as all of your pieces pretty much just need direct upgrades without much shifting around of stats. So here goes...
1)- Try to get a Zuni Pox ring with CC, armor, and vit on it. That will probably be one of your biggest upgrades, but can get quite expensive if you go with high CC on it.
2)- Zuni chest with double Vitality roll and armor roll. These can be expensive for high end ones, but very much worth it. You might wind up losing a little Intelligence since high int/double vit/high armor Zuni chests can be in the billions sometimes. But a lot of times you can find decent int (150-160ish), vit over 200, and total armor of 700-800 for a decent price. Also be sure to check on Zuni chest with vit, armor, and life % as well, as those tend to be a lot cheaper and not many people remember to look for them.
3)- Zuni boots with either AR and Armor, Armor and double Vit, or AR and double vit. These can get expensive as well, especially if you want to keep the 8% poison and good int on them. I was lucky and actually found the ones I'm wearing when doing key runs in Act 1.
4)- Crafted bracers. It tends to be rather easy to get good rolls here. Keep going until you get at least high int, armor, AR, and crit on them.
5)- Gloves. Either crafted or find a good pair on the AH. High int, AR, armor, CC, and CHD are what you're looking for. Vit, too, if you're lucky with crafting or have the gold for it.
6)- Shoulders. Try to replace that Fire Resist roll with a Strength roll instead for more armor, or higher Vitality (or a Strength + Vit roll). Vile Wards have gone down in price considerably, so you might be able to find a good pair for a decent price. Also try to get one with a higher Int roll if you can.
7)- Shifting AR. Here's the one shift I'd highly recommend. Try to get a Storm Crow with CC instead of AR, and then try to get a Witching Hour belt with AR to make up some of what you lose from the Storm Crow change.
8)- Amulet. Like the CC Zuni Pox, you stand to potentially gain a lot of dps here as well. Your current amulet has very, very low Int and rather low CHD. Try to get one with higher rolls in this area. A good Amulet to try and get if you want to buy one would be a Tal Rasha Allegiance. The extra elemental damage adds up to big dps gains with Skorn since it's a black damage weapon. If you have the gold, one with 8% or more crit and an AR roll would be a good choice. Or you can buy a rare amulet with high int, vit, AR, CC, and CHD. Not sure on the cost, though. You can also try your luck at crafting one, but it's kinda hard to get a good one this way for a lot of people.
9)- Leg armor. Try to either upgrade to a pair of Depth Diggers with high int, high vit, and an armor roll, or upgrade to a pair of rare leg armor with high int, high vit, AR, armor, and 2 sockets.
10)- Skorn. Try to get one with higher CHD, and make sure you stay above 5.3-5.4% or so Lifesteal on it.
11)- Gem upgrades obviously. Once you get more vit, just replace the vit ones in your chest with int ones. Upgrade the green in your weapon later on.
I think that about covers it for now. As I said before, you're off to a good start and have a very clear upgrade path ahead of you. Enjoy the ride. :)