Another BIG factor is how you ride- are you very upright, or more agressive (leaned forward)?
Upright calls for wider saddles, forward calls for narrower.
And yes- you have to get your bottom used to it.

All that said- if you paln to do long rides (hours), then give serious consideration to Brooks- B67 for upright, B17 for not so upright.

AND- are you riding in padded riding shorts? If not, that's step one... and don't scrimp there-Pearl Izumi Attack shorts are our favs.

A trick to keep the pain at bay- stand up for a few pedal strokes every 15 mins or so- I shift to a taller gear, and stand and pedal for 10-20 pedal strokes- it really helps.