which weapon should I buy for unholy dk with points

I am new to dk

They are both 18 points, I hope it can be used in both pve and pvp
http://wotlk.cavernoftime.com/item=45516
http://wotlk.cavernoftime.com/item=45950

another question is should Unholy use two hands or one hands in pve?

recommendation Hammer of Crushing Whispers, udk use 2 hand weps