I found best setup for this with few people is The Eldieme Necropolis. Drop in the center and start with the Spriggans in the north and south rooms at M-10/11. Then head east, around the loop and up to the ledge at M-8. With a PLD, RDM and MNK were were able to clear all 18 mobs and be back to start before repops. Did over 60 mobs in the first game day and the rest on the next weather pop.
The very best way to do this in a single game day (we had people in salvage so could not) is to go old school and get a *good* KRT party. You should be able to clear the whole loop and Virtra room in one game day.
Brytor - Sylph
LS: Legion of Altana
90 PLD, BLM, RDM, WHM, SMN, DRK