I would say getting Pink Tail eclipses attaining a level 99 party in terms of time investment and accomplishment. Don't give up! It's just like grinding on an MMO. Oh yeah, and getting Zeus Gauntlets, as well as all those other crazy items you get from random drops, such as Rydia's additional summons, are also insanely rare and require huge amounts of mindless grinding to get. The thing that sucks about those additional summons and the Zeus Gauntlets is that they're completely worthless except for collection, where as the Adamant Armor is damn good.