Question about Sword UpgradesFollow

Ok, first I have looked at the DPS chart and to be honest it seemed a bit much and a little confusing for where I am in the game.

I am currently at lvl 48 wielding Thrash Blade http://www.wowarmory.com/item-info.xml?i=17705 in my MH and Vanquisher's http://www.wowarmory.com/item-info.xml?i=10823 in my off hand. I am looking a little forward to see what my next sword or swords should be as an upgrade. I have read a lot of opinions but nothing that doesn't seem to contradict each other. I am planing on getting the lvl 60 PvP swords (warlord's blade and quickblade respectively) at 60 but other than that I am unsure as I haven't really seen anything on the AH that is better than the stuff I have.

I am not concerned with the lvl of the blade, though I would prefer it be 55 or lower but if there is a series of upgrades up to 60 then I would appreciate the info. Well, I think that about sums it up. I appreciate your help.

Oh here is my Armory link: http://www.wowarmory.com/character-sheet.xml?n=Gaijyn&r=Lightbringer

If there is any other equip that I should definitely get that I wont be out lvling or replacing really soon feel free to let me know that as well. Thanks.

Ok, so I lvled to 52 and am about to be knocking on the door to 53. I was browsing the Armory for upgrades and saw two swds that looked pretty nice they were Blade of the Wretched [link=http://www.example.com/]http://www.example.com/[/link] and, what seems like an even better choice but possibly a pain in the *** to get Mirah's Song http://www.wowarmory.com/item-info.xml?i=15806. Has anyone had experience with either one or both of these? Any particular recommendations of the two or should I stay with what I have? My armory is linked above so any constructive comments would be great thanks.