You mentioned Cor so will post my sets for it and my other 99 jobs I have available. If you should need the gear sets for them will make them up and post them later.
Armageddon is lvl 90.
Wildfire
I am trying to get Tessera Saio but current body is +4 matt/QD timer
Cor TP/Racc.
I can do a couple easy upgrades which I am planning to do just have not gotten around to them. Neck, rings, and back would be easy to upgrade.
QD
There are a couple pieces here I would like to upgrade mainly rings but have yet to have any luck with the +3 matt demons. Get a lot of M.Crit. but nothing on matt.
Used to have the QD bullet tell I shot it so need to get a new one of those.
I have done large group events in the past but not since 75 cap. Last major event I did regularly was Einherjar. Ran with a successful shell until I took a extended break from the game. I eventually came back sometime after level increases were at 85 and pretty much been a loner since.
Other jobs that I could go as would be, Vere Mnk, Gungnir Drg, and possibly sch. Sch is 500 skill sch with decent gear. I know embrava patch is coming so might not be worth it to you. I am working on Ukon once I finish Vere to 90 but that is not a open option atm. My Rdm is also very well geared but never get asked to go that.
Let me know if any of these fit what you are looking for and if wanted I can formally apply. If you want anything else I can pm you the gear sets of other jobs and we can go from there.