Which gear would provide me the biggest upgrade

[Chein]

I am currently using justicebringer on main hand and stormrune edge on my off hand.

Currently with a guild that is clearing totc 25 man regulary. Assuming i would have to wait ages for the second upgrade (DKP system), would a second justicebringer on my off hand be better or the death verdict trinket? I am using grim troll and victory call for trinket (soft cap on expertise with this)

I would have no issue getting the greave of the 7th legion for low dkp as no one else in guild can use it.

Would be gladful if anyone could help!

[Belicia]

Download and use Rawr. What is a bigger upgrade is totally gear-dependent.

[Khilbron]

I would recommend using Landsoul's spreadsheet over rawr, the calculations feel more accurate, and it allows you to do more on the fly swaps to see which you would want more.
Warrior DPS Calculation Spreadsheet - Elitist Jerks