@ OP.
I'm currently also playing a fury warrior with double Glorenzelg. I'll share my experience.
Double Glorenzelg is debatably the 2nd bis after SM/Glorenzelg, but it requires a completely different gearset compared to standard SM/Gloren or even Gloren/Crypt.
As you overcap expertise, you cannot get t10 legs (waste of stats). To put it in perspective, t10 Heroic pants have 8 less expertise than a Glorenzelg, so SM/Gloren Warriors are still exp overcapped according to Molten bugs. The biggest issue with double Glorenzelg is capping arp (Cryps/SM both have arp on them, which makes it much easier to get to 1400).
Now, you need to get 4T10, that's not really debatable, and that changes your gearing completely (assuming you have access to ICC/RS 25 heroic gear).
This is what I came up with as BiS for double Glorenzelg, after playing in Rawr for a few days and having most of the items listed. If it's remotely accurate, it's inbetween SM/Gloren and Gloren/Crypt, which should be accurate.
Head: T10
Neck: Penumbra Pendant (RS25 HC)
Shoulders: T10
Back: Vereesa's Dexterity (TogC Chest)/ EOF Dex Back (much easier to get)
Chest: T10
Bracers: Toskk's Maximized Wristguards(DBS 25 HC)/ Umbrage Armbands (RS25 HC)(Umbrage seem superior according to Rawr. Normally they are bis for SM wars, While toskk's are preffered for Gloren/Crypt)
Gloves: T10
Belt: Astrylian's Sutured Cinch(PP25 HC)/Coldwraith Links (VDW 25 HC) (both are very close in terms of DPS, I have the leather one, compensating for the loss of agi from gloves - SM wars use leather gloves)
Legs: Weirldy enough, Scourge Reaver's Legplates. There are no decent alternatives for 277 ilvl gear. Non heroic gear, go for the crafted ones. (Edit: Leggings of Northern Lights (LDW 25 HC): mail hunter legs could be useable, but not many raid leaders will allow you to roll for them. Dont have them to test, Rawr says Scourge Reaver's are superior)
Feet: Apocalypse's Advance (RS25 HC) / Blood Soaked Saronite Stompers (LDW 25 HC)/ Crafted BS Feet (IF you go with arp feet, you'll have to use the ICC Rep ring for hit)
Rings: Might of Blight (Fester 25 HC) / Frostbrood Sapphire Ring (Sindragosa 25 HC). Icc rep ring if using arp feet.
Trinkets: DBW (DBS 25 HC)/STS (RS 25 HC)..
Ranged: Fal'inrush (LK 25 HC) or Njordar Bone Bow (LDW 10 HC) . Obviously the xbow is superior, but the bow helps a bit with capping hit and is much easier to get.
Weapons: double glorenzelg (LK 25 HC x2).
As you can probably notice, pretty much every item has ARP. Feet and Gloves should get you hit capped with the talents, so you wont need to gem for hit. In addition to that, you'd probably need to gem arp in every slot as well till you get to bis gear. Only then you'll be able to gem a few 20 STR/10STR+10Crit.
Performance wise, I do keep up with most of the raid (keep in mind, the 18th place on DBS in our raids is 15k dps). I'm at the upper half usually, but I don't have the full items listed above and my gear is still a bit awkward. I'm still doing 18-19k. SM wars are at 22k, and obviously you can't keep up with them.
Trinket wise, try un-equipping/equipping one of them before the pull. This should desync them, as it introduces a 30 sec internal cooldown before it can proc. this should give you separate procs for them, which will maximize your gain from your trinkets.
If someone laughs at leather items on warrior, you most likely don't want to be in the same raid with them. Just a heads up.
Hope this helps.