I'm not sure how we can come to a solution that would satisfy everyone. Rewards for doing something special should be unique to that. Just don't put it in a time limit since people tend to do things as different pace.
Although, first thing that came to mind is how the Raiding is doing it. Normal Raid got their own loot while the Savage Raid got their "upgraded" version of the same loot. So maybe do something like that?
PvP rewards could be the same but upgraded somehow. Dyeable? Maybe some extra bitz to it? That way both sides gets the loot and the ones that goes the extra mile gets a more shinier verison to show that they have actually done it.