Well it's not that straight forward to answer that cuz you get different crucial buffs from different buffers:
Prophet: zerk, acumen
Shilien Elder: empower, wild magic
Eleven Elder: clarity, wild magic, prophecy of water
Bladedancer: on the cell, and to lazy to look skill names up, but it gets multiple nuke buffs.
If I was forced to only have one box assisting my nuker, I would go with SE.