I would recommend frost for lvling.  I find it so easy to grind when you kill a mob and he only does to you about 5% of the damage you have done to him...

If ya stay frost when you hit 70, you might wanna do the frozen shadowweave for PvE and get the Arena Gear for PvP.  The Arena gear is also decent for PvE it tends to have lots of crit, where the shadowweave doesnt, but it lacks in spell damage... 

I would definately recommend the spellstrike hood and pants though.