Go standard unless:

no healer on team: go Army of the Dead lvl 10, Relentless lvl 13 and Legion of Northrend

if they do not have good cc ex: Brightwing Muradin etc go Bitning Cold

If you face extrem burst ex Nova Jaina Nazeebo Bloodlust Illidan you can make a agrument for Hardened Shield
Otherwhise only go for this if you're behind with Summon Sindragosa or need it more then the sustain from Legion of Northrend

Arthas is a warrior who pacs some dps alongside his tankyness. Since he is able to put out nice dmg even after the Evenom nerf happend were still able to do what we allways did: Slow, Root and kill stuff.

The builds work like this: The standard build is what i typicly go for, however there are some stuff you need to keep in mind:

Lvl 13: Biting Cold Vs Relentless

I prefer Biting Cold especialy when you have a healer with you, but if your upp against allot of CC like Brightwing Muradin E.T.C. Diablo Anub'arak etc

I like to go for the standard build and alter it to the games need, ex get Relentless vs allot of cc or pickup Army of the Dead when you are the only tank with allot of squishys like Jaina And lack something like a Raynor who can semi tank abit. Also get Army of the Dead if you do not have a healer with you.

As mentioned in the guide only go with "Dual Warrior" if you're paired with a Diablo or Muradin both if which have realy low dmg but bring allot of controll. Playing this makes your Summon Sindragosa Crutial since its amazing setup for [Muradin]] to get a double stun or [Diablo] to get a nice Lightning Breath of.
I have not yet tried this build but in theory it should work since dubble warrior gives you allot of controll but lacking dmg.

This was my first Guide, if you feel like i've missed anything or want me to go into more detail on any of these points feel free to let me know. I hope this guide will help you out with the Lich King Arthas, He brings ALLOT of controll and a good amount of burst even post envenom.

Yours Truley, Blazeshard