Easy Weapon upgrade(s)?

Hello. I currently hover near a gearscore of 4.2 and my weapon is OK at 600 gear score. It's blue grade, simple 2hand sword for my DK. I'm looking for any possible way to get an upgrade? Perhaps purple grade or 700+ gear score? My guild is doing a raid this weekend but I won't be able to join so is there any vendor or perhaps heroic dungeon that drops any 2h axe, mace, sword? I'll be checking back on this forum later on, thanks y'all

Easiest would probably be any weapon from for/pos/hor nm/hc.

Pit of Saron Normal: http://wotlk.cavernoftime.com/item=49802
Pit of Saron Heroic: http://wotlk.cavernoftime.com/item=50267
Halls of Reflection Normal: http://wotlk.cavernoftime.com/item=49839
ToC 5 HC: http://wotlk.cavernoftime.com/item=47493