Don't forget to get another 30% IAS on the Maul. For a WW barb it's VERY important to reach the fastest WW speed. It's like increasing your total damage by 1.5 times, bringing it from a 6 to a 4 frame WW. Cheapest option is 2 Shaels, but Jewels of Fervor with nice prefixes (i.e. 40% ed) are best.
Throw 3 Sol runes in each of the Helm and Armour sockets and you'll have a REAL immortal king. 21 straight PDR will almost completely negate the Tomb Viper's bugged poison cloud damage, and serves very well in most other places too.
Don't place any more than 187 in strength either, since the Gloves and Belt grant 20 + 25 = 45 strength, and 45 + 187 = 232 for the armour.