A couple really helpful items for the spec, Stone of Jordan, Mighty Belt with Life Steal / Reduced Weapon Throw Cost.
It's worth noting, both items can reach a reduced by 5 cost on Weapon Throw, but you can actually only reduce the cost to 1, even with both items having reduced by 5.
On the note of a Skorn, though... I've never actually tried it due to being too cheap to buy a Life Steal version. So I've no comment, there.
(Also: When Searching for a SoJ, change the Search to All Armor Types, Search Bonus vs Elites and Reduced Wep Throw, since you can't search for cost reduc. on Rings alone)
Another recommendation I have, is grab a decent Life Steal, Str, Crit Dmg Mainhand paired with a Three-Hundredth Spear, they can roll up to 50% Weapon Throw / Ancient Spear damage, so it is useful for sure. I'm currently running a 880 DPS Axe in my Mainhand, and 890 DPS Three Hundredth Spear with 46% Dmg on Spear/Throw in my Offhand/
In DPS tests on MP9-10 Siegebreaker my Throw/Spear DPS is pretty competitive to Whirlwind (maybe 50K lower, including the fact I'm having to constantly run as Throw Barb), though my survivability makes me have to be careful when doing MP7-8 Ubers due to lack of superstition.
One unfortunate thing I've noticed is while doing Ubers, you will occasionally just be SoL for WotB/Thrive on Chaos due to bad luck. Just try to keep your Fury low when using a 1 Cost Weapon Throw, considering a successful No Escape proc will be generating a lot of Fury.
It's also worth noting that despite me using Weapon Throw / Ancient Spear for Ubers, there are a couple other options for the build. HotA / SS / Rend being some Spenders you can use, while keeping Fury easily.
Lastly, I'd carry a couple extra pieces of gear to get some more survivability (Switching out your SoJ for a Litany, or something to the like) due to Throw Barb having the risk of getting into a sketchy situation. But, overall I'm in love with the spec. It's something different, for sure.