[Droxx]

IMO, Wis is useless on a shaman unless you're constantly coming down from FM, being able to capitalize on having more mana. But whether you have 2000 mana or 3500 mana you can only regen mana at a certain rate. Mana pool is much less important than the ability to regain mana (through Canni for a shaman).

HP (and STA) give you the theoretical ability to recover more mana through Canni, as well as giving you more survivability.

TL;DR I think STA is best. It really doesn't matter though.