Get all the Wondrous Tails done, but wait until job changing to Reaper to hand it in.
Get most of the exp-related Challenge Log stuff to 2/3 or 4/5, then max out as Reaper.
Stock up on tomestones. Maybe tomestone gear will become cheaper when 6.0 drops? I hope? If so, buy level 80 stuff for Reaper and begin expansion MSQ!