If you want to be BiS, you need antorus mythic gear. Beg and plead your way into 4 full (i.e. tmog, usually skipping Eonar) mythic runs, make sure you use them to complete the Eonar skip quest inside. Then make your own groups since you'll have the skip already. In my experience, 120s have no problems joining your group if you have the skip. Anything socketed is great. Once you're rocking 240+ ilvl in all slots + 2 legendaries, you can think about optimising stats, gems, etc. Heroic antorus is also good to run, in case you get some socketed WF/TF items.
Alchemy trinket may be a good choice for PVP to make the most of healing potions.