Trinkets would indeed be the best upgrades, you have several options, the easiest at the moment to obtain is the black heart from toc 5 heroic, I believe thats a small upgrade, the hp+ armor proc is incredible for it's item level, although it could be arguable that the straight stam is better from your current ones. The other trinkets you can try to get are juggernauts vitality from toc25 and togc 25, i don't know if it has a different name for alliance but its 198/216 stamina with an hp increase on use effect. Also theres the corroded skeleton key from badges which is probably the best thing you can get at the moment with 228 stamina on it and an absorb use effect. The only other trinket of note atm is the unidentifiable organ from icc 10 which is bound to drop for you some time soon, the armor is great and the stamina proc is really nice for certain fights. If you can get the togc25 trinket + skeleton key i would use those then swap in the unidentifiable organ for certain fights/trash.